NB - 83 Mustang drivetrain
 

Hi folks,

It looks like I have posted enough on the Introductions page to start a build thread. I bought a 2002 LS at auction in late October, after roaming this site for close to two years, and scheming. I've owned a 1983 Mustang GL since college (drove it a few times in high school). Over the years I've replaced about everything and after a season of autocross have decided it will not take me where I want to go - driving to and from autocross and open track / HPDE events and having a great time.

So, best of both worlds - the handling, brakes, light weight, top-down general fun of a Miata with the best part of my Mustang - the '88-based 306 (carbureted; 275whp, 300 ft/lbs) with a T5.

This will start slow since the NB runs (203k miles). I plan to do some autocrossing and perhaps an HPDE event this summer, and then get to work on the driveline transformation next winter. By then I will have an insulated garage. :-)

As noted on my intro page, I lucked upon a winner - lots of aftermarket parts, including Eibach springs, Koni shocks, and a Koyo radiator. I've bought Hawk HPS pads to go in all around, I'm changing the fog lights to brake ducts with LED DRL surround, and I am adding some bracing - stitch welding around the door sills, 1" square along the bottom pinch weld. I also plan a rollbar install (still deciding BBFW or custom local) with eventual door bars, an install of my Momo racing seat from the Mustang, harnesses, 2" tube rather than subframe braces, and I may need to drop the floorpan. I'm still sorting out how I fit with a helmet. I'mm definitely staying with the soft top - my Mustang is a T-Top and I love the open-air approach.

Lots more to come, slowly. I have learned so much from this forum already and look forward to the give and take over the next few years.

Sounds like a good plan.

always look forward to new build ideas
 

awesome for jumping in, I am hoping to finally get back to my build after a 14 month delay, started a new business last year and just now starting to get the time to think about returning to my project. Remember to have fun and post pics and ask questions. This community is excellent and offers some great advise..

Movieboy4fun

Agreed on all instances!

I was working on a few things over the winter. It is now getting warm enough that it is comfortable to spend time in my NE Ohio garage. I've pulled all of the interior but the dash, and did some seam welding around the doors (fusing the various layers together). I'm also removing the rusted-out fog lights and installing front brake cooling ducts in their place. I had purchased stock-sized Centric rotors and close-out Hawk HPS+ pads from Tire Rack. When I dug in to install them, I found that all four calipers were in various stages of complete failure / deterioration. So, I picked up some Powerstop rebuilds from Summit. I should be able to trust the brakes now (flushed all of the oil fluid out as well)! Last item was to weld 1X1 square against the sill seam, to provide a reliable jacking point, and to eventually tie into a reinforced subframe rail under the seat.
https://cimg4.ibsrv.net/gimg/www.v8m...05e1bb4b65.jpg
Cooling duct-inside. 3" at opening, 2.5" at spindle
https://cimg8.ibsrv.net/gimg/www.v8m...f487698e90.jpg
Seam welding
https://cimg4.ibsrv.net/gimg/www.v8m...6c1bb3838e.jpg
Completely shot!
https://cimg5.ibsrv.net/gimg/www.v8m...2c0b6873fc.jpg
Yep, the rear brake pad actually flaked off the backing plate.
https://cimg3.ibsrv.net/gimg/www.v8m...dbe1042567.jpg
Rusty old front caliper
https://cimg7.ibsrv.net/gimg/www.v8m...7c5ae9d289.jpg
New front brakes
https://cimg6.ibsrv.net/gimg/www.v8m...59add8ca3a.jpg
New brakes!

Sill reinforcement.
https://cimg9.ibsrv.net/gimg/www.v8m...934a23f6ca.jpg
Brace under pinch seam.

I've been reading and researching, and enjoying the heck out of my Miata. I've done a lot to it over the past year, and amazingly, it is still running strong with the stock engine at 205k. My plans have changed - going to sell off the Mustang in the spring as a complete car, then get a salvage '95 Mustang 5.0L. I understand that the accessories leave more room in the front, and the transmission comes closer to fitting in the stock shifter location. I bought a rear subframe so I can start working on the diff mount. My plan is to do as much as I can before I start taking the driveline out, because there is obviously no driving until the new driveline is complete. :-)

https://cimg6.ibsrv.net/gimg/www.v8m...80b93298db.jpg
Hard Dog Roll Bar
A Hard Dog hard top, single diagonal went in. Seemed to be the best compromise of far enough back and as tall as possible. Still ended up being quite a challenge fitting me under it. :-)

https://cimg5.ibsrv.net/gimg/www.v8m...0dccae2616.jpg
New radio
https://cimg7.ibsrv.net/gimg/www.v8m...e078806053.jpg
New switch panel
https://cimg8.ibsrv.net/gimg/www.v8m...bf7c2638df.jpg
Subwoofer

Installed a new head unit and speakers, with separate amp. Also built a subwoofer box with a separate amp. Not enough room for a subwoofer in this car! Since I had a single-DIN unit, I made a switch panel underneith and installed a Volt gauge in a blower vent for good measure. Not essential to a V8 installation, but I needed my tunes! Working with the factory Bose wiring was difficult - I read a LOT of posts getting this done.

https://cimg5.ibsrv.net/gimg/www.v8m...c5f255ff49.jpg
AutoX ASCC
https://cimg7.ibsrv.net/gimg/www.v8m...32bb977c49.jpg
AutoX NORA
https://cimg0.ibsrv.net/gimg/www.v8m...046eb93d9d.jpg
Nelson Ledges
It was a very active summer - several events with the NE Ohio SCCA chapter and the Akron Sports Car Club / NORA. Got to enjoy sharing the car with my son. :-) Also did an SCCA "Track Night" event at Nelson Ledges. That's where it became obvious that the stock driver's seat had to go - I was way too tall for the rollbar, and sliding all over that leather seat. This car is so much fun to drive!!!

https://cimg1.ibsrv.net/gimg/www.v8m...63c90e06d9.jpg
Old and new

The old and the new, out for a wash. My electric daily driver is in the background. An eclectic collection, for sure!

https://cimg7.ibsrv.net/gimg/www.v8m...0846b25910.jpg
Lowered floor
https://cimg9.ibsrv.net/gimg/www.v8m...a87aba4028.jpg
Trimmed seat
https://cimg0.ibsrv.net/gimg/www.v8m...fc4acc0581.jpg
Seat and harness
https://cimg1.ibsrv.net/gimg/www.v8m...a5a3fd1878.jpg
Harness Bar1
https://cimg2.ibsrv.net/gimg/www.v8m...bf5eebaaec.jpg
Harness Bar2
I pulled the Momo racing seat out of the Mustang and had seen pictures where it would fit in a Miata. It took several attempts that became increasingly difficult, but I ended up cutting the floor pan on three sides, bending it down, and bending up and welding in sheetmetal, with reinforcements below. It was the only way to get me under the rollbar. I needed to retain a slider, since I share driving duties with my son, so bolting it directly to the floor was not an option.
Installed a racing harness, too. I intended to keep the seatbelt operational, but the seat interferes with the belt. So, I clip in every time I drive now. Part of the fun. :-)
Not much room for a crossbar for the shoulder straps with the subwoofer, so I got creative.
The racing seat / harness make a world of difference! Firmly secure; no more bracing with my legs around turns. Or holding onto the steering wheel for dear life. :-)

https://cimg4.ibsrv.net/gimg/www.v8m...90c68c0d36.jpg
Halo DRLs
https://cimg5.ibsrv.net/gimg/www.v8m...abdf014344.jpg
Pitt Race

Halo LED DRLs so I am a bit more visible. People miss this car completely in the mirrors sometimes.

My last event of the year - SCCA Track Night at Pitt Race. Ended up boiling the brake fluid in the third 20-minute session. I bought some Motul the next day and bled the system. So much for "DOT 4" brake fluid. Surprisingly it was the rear pads that got so hot. Looks like I need to duct some air to the rear rotors.
I'm currently cutting the hood - R-Theory hood vents and Aerocatch latches, as well as Flyin' Miata hood struts. All necessary for the eventual V8. :-)
I'll post some pictures when I finish the hood.

The V8 conversion has taken a turn for the better. I now own an extra rear Miata subframe and a complete rear subframe from a 1997 Thunderbird (V8, so its an 8.8 rear). I'm going to start working on DIY differential mounts soon!

Per this video, are there drawings for the DIY mounts on this site somewhere? I've done a lot of searching, but nothing....

I've visited this page about a dozen times....
https://miatav8.blogspot.com/2014/01...gftS89EvGEH8No

I'm a but nervous about making sure the 8.8 is aligned properly to the Miata subframe, so any measurements I can find are a plus. I will also be taking measurements off the stock diff and axles, since they are still in the car.

Thanks!

I've got some nice PDF's from another forum member that I will try to post here or on the blog. Also a pic from Facebook showing what might happen if the gussets shown on the blog are omitted. I probably need to document the gussets as well. They really need to extend over to the curved part of the subframe as far as practical I think the lack of gussets and the possibility that the urethane bushings were not properly modified to fit the thickness of the angles contributed to this situation.

Mike
https://cimg1.ibsrv.net/gimg/www.v8m...e91693d90f.jpg

That is a pretty significant frame split. Thank you for the advice. And for posting the drawings! Very, very helpful!

Bryan

I neglected to include that the Facebook post mentioned that there had been wheel hop issues previously. Wheel hop is like taking a jackhammer to rear suspension parts.

Mike

Thanks, Mike.

My '83 Mustang used to have wheel hop like crazy until I built a torque arm / Watts link rear end for it. So I know what to watch for. :-)

I think I'm going to full poly bushings in the suspension, as well as the diff mount to try to discourage wheel hop. That and I won't have the crazy torque some on this board have.

Bryan

It's been a busy winter. I found some great Black Friday sales and made some upgrades that will help with autocross now, and will be even better when I go to a V8. I'll post a few pictures this weekend.

In the meantime, I have a couple of questions:
Per power steering, it looks like it is okay to use a Ford power steering pump, as long as you can adapt the fittings to the Mazda power steering lines, correct? I have also seen a LS build thread where they used a pulley from a Dodge minivan on the Mazda pump. If I can find a pulley with the correct diameter and width, is this a good option as well (knowing I will need to build a custom mount for the pump)? Either way, I would like to use one serpentine belt for all accessories (I won't have AC).

In looking at lots of build threads, I'd really like to go with mid to long tube headers if possible. I have read that moving the engine an inch to the passenger side helps. If I go with the V8R tubular subframe, does this free up a lot of room for LT headers? Are there still issues with the frame rails? It sounds like steering shaft clearance is the major defining factor? I'd like to go with a non-custom Tri-Y if I can.

Thanks!
Bman

I started with Aerocatch latches (so I could remove hood latch) and R-Theory hood vents. I went with the hood vents that seemed to have the best low-pressure / extraction location. I found that following the hood reinforcement and drilling holes along the perimeter from below helped a lot with aligning the template and then cutting from above.
https://cimg6.ibsrv.net/gimg/www.v8m...fb4e2d262a.jpg
Aerocatch latches

https://cimg4.ibsrv.net/gimg/www.v8m...bfe7e1182a.jpg
R-Theory hood vents drilled outline from below
https://cimg7.ibsrv.net/gimg/www.v8m...7409f7cf15.jpg
Trace R-Theory template from above
https://cimg9.ibsrv.net/gimg/www.v8m...062201e11d.jpg
R-Theory hood vents complete

Astute picture viewers will also notice the Flyin' Miata hood struts that allowed removal of the hood prop rod. Making room for eventual radiator and air intake. :-)

Next up were brake air ducts for the fronts. They are 2.5" and the "half moons" are to direct air toward the center of the rotor. I'll hook these up to the previously installed front bezels on track days.
https://cimg2.ibsrv.net/gimg/www.v8m...816cb99f43.jpg
Front brake air duct
https://cimg7.ibsrv.net/gimg/www.v8m...7cbf61eb96.jpg
Front brake air duct air deflector

Next, the old, rusty coilovers came off (Racing Beat springs on Koni Yellow adjustables).
On went Fortune Auto 500 coilovers, with heavier springs (10kg/mm front, 7kg/mm rear). I went this direction after reading a number of reviews, and studying V8 spring rates. I am THRILLED with these coilovers. The ride is actually better than the "softer" springs, and combined with new sway bars the handling is amazing. I ran an autocross with my son a couple of weeks ago and loved the responsiveness.
Whiteline front sway bar set on soft; 5X rear sway bar sent on medium.
I’ve now set the ride height – 12.5” front and 12.75” rear, center of wheel to lip of fender. This was about 1/2" front and rear higher than it was (it was too low). Nice that I can adjust ride height now! I'll readjust when new driveline is in.
I had it re-aligned to the settings I inherited with the car, since it seemed very balanced that way, -1 degree camber front, -2 degrees rear. I'll likely take some rear camber out when I get the V8 in as I'll need the full contact patch for the torque. :-)
https://cimg4.ibsrv.net/gimg/www.v8m...ca4703c150.jpg
Old coilover
https://cimg5.ibsrv.net/gimg/www.v8m...0b94653e62.jpg
Fortune Auto 500 fronts, 10kg/mm, Whiteline sway bar, FM adjustable end links
https://cimg2.ibsrv.net/gimg/www.v8m...d1b92b3139.jpg
Fortune Auto 500 rears, 7kg/mm, 5X sway bar, FM adjustable end links

After viewing video of what happens to Miata front sway bar mounts with a larger bar, I fabbed up my own braces with longer bolts and 1X1" square tube.
I also got a set of 5X tow hooks. The only color they had at the time was green, but fortunately Eastwood chassis paint is available in silver. I'm using quite a bit of that.
https://cimg1.ibsrv.net/gimg/www.v8m...a9dec9258c.jpg
Front sway bar brace
https://cimg1.ibsrv.net/gimg/www.v8m...35e89aecf3.jpg
5X front tow hook, painted
https://cimg1.ibsrv.net/gimg/www.v8m...3c593a2973.jpg
5X rear tow hook, painted and installed

I had a hard enough time staying in the passenger seat during autocross runs with the old suspension; typically holding onto the seat with both hands for dear life. I didn't want a single-piece race seat for the passenger side, as I wanted to keep it seatbelt and wife-friendly. I bought a Planted braket (very well made) but found it put the seat too high, so I fabbed a new bracket out of Home Depot C-channel. I thought the channel would be stronger than flats. I added an anti-submarine mount and cut a hole in my brand-new OMP Style sport seat (I used a great seatbelt bezel from TRE Performance). I got a Crow harness to match the driver's side, and already had the harness bar to tie into. Since it's the passenger side, I didn't have to mess with an adjustable slider. I cut out the rear seat mounts and bolted it to the floor in the rear (with large backing plates). I used the factory mount in the front.
The seat is very comfortable; I bolted the seatbelt receiver to the trans tunnel (also with a backing plate) and find that it is very comfortable for ice cream runs. And with the harness, the passenger no longer needs to brace on autocross runs!!
https://cimg1.ibsrv.net/gimg/www.v8m...8034ff4c6f.jpg
Fabricated passenger seat mount

https://cimg1.ibsrv.net/gimg/www.v8m...982a75ad5b.jpg
Passenger seat mount with anti-sub belt mount

https://cimg6.ibsrv.net/gimg/www.v8m...03321a7b13.jpg
OMP Style and Crow harness

I read a post somewhere about using surgical tube to tie up the anti-sub belts. I did this on both sides and it is GREAT for keeping the belt out of the way when using the seatbelt, and for finding the belt when jumping back and forth in a 2-driver autocross car. No more anti-sub belt falling through the seat!

https://cimg8.ibsrv.net/gimg/www.v8m...1590716123.jpg
Thunderbird rear end with 8.8
https://cimg6.ibsrv.net/gimg/www.v8m...45d0a1af59.jpg
1992 Tbird 5.0L
Of greater relevance to this forum than my above improvements, I found a complete T-bird rear subframe at a local salvage yard with an 8.8 3.27 limited slip in it. That diff has been removed from the subframe and is on my workbench, and I am acquiring parts to rebuild it. Since I happened upon a limited slip, I'm going to rebuild the clutch packs and see how it lasts.

Separately, I found a nearly-complete 1992 Thunderbird 5.0L nearly complete in another local salvage yard. It has 165k miles and is complete except the alternator / AC bracket. I'll start tearing it down soon to see what I have; at the very least a core.

Between these and an extra rear subframe to start fabbing up a diff mount, I am now committed to the V8 Miata project.

My plan is to rebuild / fab as much as possible before I remove the driveline from the Miata, so I have as little "down time" as possible. I'll be in withdrawal when I can't drive this thing!!

I didn't see any response to your questions, perhaps everybody is on a Facebook page somewhere. I now have 2 302 Miatas, both have the original Ford PS pumps and serpentine belts with no problems. I don't have the fittings documented, but it must have been pretty straightforward.

One of the sections of that blog shows some pics of the fitment of some Ebay tri-y headers, but the fitment is based on the subframe I built, so can't really comment on your chances with a V8R sub. Those Tri-Y headers are a copy of the ones Shelby used on the original GT350 Mustangs, which had a very narrow engine bay, similar to Miatas, so it looks to me to be a good place to start. They are available in painted steel or stainless, the painted ones may be easier to modify if necessary.

My feeling on the offset is that you should put the motor where it best fits. As far back and as far to the pass side as possible. Corvettes since 84 and all Vipers have significant offset toward the passenger side, for the same reason as V8 Miatas, steering clearance. Look closely at the mounts on the V8R subframe for LS motors. And it can only help your side to side weight balance with driver.

Thanks for supporting the forum, there's a ton of info in the archives relating to Ford conversions and now you are part of that.

Mike

Hi Mike. Your responses are VERY helpful. Thank you!

I'm now satisfied that I can go with the Ford PS pump and make it work. I've spent time on your (GREAT!) blog; I'll visit it again. My question about the headers is really if the subframe is the only limiting factor, or if the car's frame rails come into play. From what I can tell from pictures, the exhaust side of the cylinder heads exits below the level of the frame rails, but it is hard to tell. If only the subframe comes into play, I think the V8R / tubular one likely frees up pretty good room for a close-fitting header. I've seen at least a couple fabricated long-tube SBF headers on this forum. And of course V8R / Kooks has a long-tube for the LS crowd (I emailed Kooks and they don't have an off-the-shelf SBF application for a Miata).

And yes, I will certainly post any lessons I learn along the way on my build.

Again, thanks.
Bryan

Hi Bryan,

Great work thus far well done.

I can attest to the use of a Ford power steering pump on the Miata rack without issues. I use the Ford Explorer GT40P steering pump and accessories brackets on my car. You are correct with the long tube headers and the subframe. The subframe is the limiting factor here. There is ample room for a 1 3/4 inch long tube exhaust setup. It will need to be custom made but there is room to make it work and make it work well. Both V8R and Monster Miata can do a custom subframe. I use the Monster Miata subframe. My setup is trickier than yours because my car is RHD so the starter AND the steering arm are on the same side. Your car will have much more clearance. Not that mine is bad, its actually pretty good (see my build thread) considering the stuff that's packed in there. But the steering on the other side would have made it a breeze.

My advice, get a custom subframe and exhaust if you want it to perform, need it neat and want clearance everywhere.

cheers

Thank you much for the additional advice, and for confirming both Ford steering pump and long tube headers. I've spent a lot of time on your build thread!

Cheers,
Bryan

I can attest that a tubular subframe definitely make long tubes easier...(if that is such a thing).

Great buld BTW!!

awesome work on your build, just wanted to add that the T-bird 5.0's have the E6TE heads. If you are doing any performance upgrades you will have to toss those heads in the scrap metal bin. There is a fin at the intake valve to promote swirling, may work for low RPM stuff but did not work well on the track. I changed to Mustang E7TE heads and gained 1.2 seconds in the 1/8th mile with no other mods.

Hi folks,

Thanks much for the additional relies.
"Engineer," I revisited your build page. Those are fantastic Tri-Ys! I don't suppose you have any pictures off of the car??? I was planning dual 2.5" pipes to a merged 3" at the rear (through a Corsa muffler - I used to work there and love the sound). Looks like this will work out fine, particularly since my block is not a stroker.

"Trueblue," I also appreciate the confirmation on the tubular subframe, long-tube headers. I'm running long-tubes on my '83 Mustang and think they are the only way to go. Any dyno comparison suggests this is the case. I'm planning a longer-duration cam, and it seems that's where the scavenging of a long-tube is most beneficial.

"Movieboy," thanks. The heads will be ditched in favor of AFRs. On my '83 Mustang build I hand-ported a set of E7TEs. It was a major budget compromise at the time; one I don't plan to repeat on the Miata 5.0L. :-)

My sons are raising a major "save the Mustang" campaign. So my latest thought is to go back to my original plan - pull the 2k mile 306 from the Mustang and put on a new clutch / new rear main seal and designate that the Miata engine. Then do a re-hone / re-ring and drop that back in the Mustang (with the hand-ported E7TEs). With the Miata in the garage, the Mustang will never see track or autocross again, just ice cream runs, so it should fare okay with a mild rebuild. The plan evolves....

Hey Brian,

So sorry but I dont have any pics of the Tri Y's off the car. But I can tell you that they are 3 separate pieces per bank and they do NOT have a common flange at the head. Each cylinder has its own little flange, which makes it possible to remove them and put them in in sections, as a full 4 cyl; wide solid flange just wont fit in.. The setup is 1 3/4 tubes from 2 cylinder pairs into a common 2 inch pipe. Then its 2 x 2 inch pipes into a 3.5 collector then to a 2.5 inch outlet. Then its two by 2.5 in pipes until before the diff. Then it merges into a single 3 inch pipe. Sounds great, not noisy at all and packaging is neat.

cheers

Very helpful! Thank you much for sharing all of the details. If I can't get that replicated, I'm not working with the right fabricator. :-)

Again, if this is working for you on a stroker, I know it will keep up with my 302.

Cheers back (I always liked that greeting),
Bryan

Well, after a summer of autocross and track lapping (I do love this Miata!), the Miata developed a bad vibration around 70 mpg. My shop re-balanced all 4 wheels and indicated some play in the bearings where the driveshafts enter the differential. So, they think it is driveline vibration. That means, IT'S TIME TO DROP THE DRIVELINE AND PUT IN A V8!. I'm working on the 8.8 differential mount with an additional rear subframe I have. I also just ordered the V8 Roadsters mountless tubular front subframe. Does anyone know the tubing size on the V8 Roadster subframe? Looks like most everyone uses the front "up" bars to attach their frame mounts. I'm buying some steel for other reasons (door bars) and would like to go ahead and get some stock for the motor mounts as well. Thanks.

If you keep the Tbird front drive the Alt.sits slightly lower than the SN95 Alt. just a FYI tidbit.

Thanks, Trueblue! When I bought the salvage motor it was missing the alternator and bracket (the power steering pump was on there, which I plan to retain), so I think I will be going with custom / fabricated accessory drive brackets. I appreciate the tip though.

I got a response from V8 Roadsters, in case anyone needs this in the future. The side rails are 2"X1" rectangle (I thought they looked square), and the main hoop is 1.5" I can only assume that the uprights are 1.5" as well. I'll likely attach the motor mounts to these, as that appears common. I should have a subframe in 4 weeks!!

As an aside, I am a frequent reader of the MotoIQ site, mostly folks from Sport Compact Car that I read avidly back in the 90s. They built a motorcycle-engined NA Miata and used a V8R subframe and ran some interesting cross-bracing. There may not be room for that with the 5.0L oil pan, but I am considering the advantages of a subframe cross-brace.

Cheers,
Bryan

Hi Mike,

Thanks again for providing the drawings. They have been INVALUABLE the last couple of weeks as I have finally been working on the differential mount.

Bryan

Looks like I missed several steps in my updates. I rebuilt the Ford 8.8 last October on my workbench - new friction plates, seals, and a coat of paint.
https://cimg5.ibsrv.net/gimg/www.v8m...c8aa710b74.jpg

I tore down the 5.0L and polished the crank journals.
https://cimg2.ibsrv.net/gimg/www.v8m...cebe7cdb8b.jpg
I sent the block out and had it machined 0.030" over, and had new pistons mounted on cleaned rods. I've painted the block and put main bearings, the crank, and the cam in. I will focus on that once I get the differential mounted.
I'm benefitting from a LOT of people going before me. I'm taking a slightly different approach to the differential mounts. I'll explain and post more when I have a complete set of pictures, but I at least got the front mounts welded on last evening. After all of the cutting and drilling, it's nice to be able to start welding things together!!
https://cimg7.ibsrv.net/gimg/www.v8m...15db6e42b5.jpg
Front differential mounts on subframe

I had some productive garage time this weekend. My thanks to everyone on this forum and on YouTube that have posted about mounting a Ford 8.8 someplace new. I've gathered pictures, drawings, and videos to borrow a lot of great ideas. I don't trust the strength of my welds, so I redesigned to run a bolt all the way thorugh the subframe, front and rear (7.5" front, 6.0" rear). I have reinforcement plates on the "top side" front and rear as well. I also ran steel tube through the subframe rails front and rear and welded / covered them up, to ensure that I couldn't crush them later. I cut up and studied the Thunderbird subframe before I scrapped it and found that the differential was mounted THROUGH the subframe rails, rather than ON them. I thought I should do the same. The extra long carriage bolts are there to help me line everything up. I found it was not easy to drill successive holes and keep them in line (not having a boring machine). I have Grade 8 bolts for the front on the way. I'll wait for some warmer weather to paint it, and its done. Now I can focus on building the engine!

https://cimg6.ibsrv.net/gimg/www.v8m...2c8e725486.jpg
Hand lay-out and tools
https://cimg5.ibsrv.net/gimg/www.v8m...cfee603e23.jpg
Front mounts
https://cimg3.ibsrv.net/gimg/www.v8m...eb36ac8396.jpg
Extra holes do not go all the way through - measuring for inserts.
https://cimg8.ibsrv.net/gimg/www.v8m...3388af684c.jpg
I cut this plate in half. More surface to weld to, and shimmed up the 1/8" gap.
https://cimg2.ibsrv.net/gimg/www.v8m...f7237a6b21.jpg
Rear mount complete. Added extra brace to seam of rail. You can just make out the bolt heads on the back side, welded in place so they function as studs.
https://cimg8.ibsrv.net/gimg/www.v8m...e0b71757fe.jpg
Completed mounts.
https://cimg8.ibsrv.net/gimg/www.v8m...f0e396a347.jpg
Top reinforcement plates.

I was surprised to find a 1/8" gap between the rear plate and most the length of the subframe rail. I didn't trust my welding that much of a gap. Maybe this is why this part of the mount has failed a few people? Anyway, I cut the plate in half to give myself more to weld to, and shimmed the gap with 1/8" steel strip. Along with the gusset to the rail seam, I expect this to be pretty strong. Most of the force will be transferred through the pass-through bolts anyway.
As I noted above, grade 8 bolts 7.5" long are on their way for the front mount. The overly-long carriage bolts were very helpful to line all of my holes up.

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ARP main studs in
Now that the rear subframe is complete, I can work on the engine! I had laid the main bearings and crank in before, but just used the original bolts temporarily. I installed the ARP studs and torqued them properly. The crank still spins freely - a good sign. I need to press new ARP bolts into the connecting rods and I'll install the pistons.

Long overdue for an update.

I pulled a Thunderbird 5.0L for the "SN95-like" accessory drive. I'm finding that there are a few notable differences between the Thunderbird and true 94/95 SN95 Mustangs. Most prominent so far has been the water pump. I bought a nice, Stewart 94/95 water pump. It matched up fine to the timing chain cover, but the hub had a different bolt circle. My previously painted Thunderbird pulley didn't match up. Fortunately I found this before installing the water pump, so back to Summit it went, and I bought a dedicated '92 Thunderbird pump. Impeller was the same design, so I'm hoping it will function as well. It was that or buy a 94/95 Mustang water pump pulley, and I decided to go this route. I had to chase the threads in the water pump pulley hub to get the bolts in all the way (they are 5/16-24 threads).
I also got the power steering pump off and replaced it (Thunderbird non-variable-effort pump). In case you want to replace the goofy 6-point-head mounting bolts (E-Torx socket to remove them), they are M10-1.5 by 30mm. I got some button head stainless bolts because there is not much clearance to the pulley.
I'm currently wrestling with the Summit-sourced harmonic balancer (SUM-163302). I have the original Thunderbird balancer and one off my Fox Mustang side by side and they are identical. When I assemble the "maximum depth" setup on the Summit balancer, the crank pulley is not in line with the water pump pulley. Looks to be about 5/8" too close to the engine. Odd, since I would think this is replacing a very common balancer size (4.19" deep, measuring from bottom to top of bore, top being the lip that aligns the crank pulley).

There is a spacer needed to position the crank pulley correctly... Give me a few and Ill post the number.

Here you go

Spacer

Hi TrueBlue,

Sounds like you had this problem, too! Thanks much for the response!!

Bryan

The other thing I meant to post for future users of the SN95 accessories is that the inside edge of the accessory belt appears to be close to 4.5" from the plane that the timing chain cover bolts to. Same plane formed by the front face of the cylinder head on the passenger side, at least with my AFR heads. That should help get all of the accessories aligned. I'm using the stock power steering / AC bracket (minus the AC), but will fabricate something to hold the alternator. I'll post a more exact / confirmed measurement when I have the full accessory drive assembled.

It is time
 

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Finally getting the swap started!!
To quote Rafiki from The Lion King, “It is Time!” The original driveline is distressed enough that I don’t want to tempt something exploding. Time for the V8 transplant! Hopefully I will be updating with progress regularly this winter.