Bought Hedman headers and can't fit! Need help please!
 

Hi guys, long story short, I'm rebuilding the "built" v8 Miata I bought about 2 years ago. I got rid of the crappy headers he had on there (explorer headers he cut to fit) and bought the Hedman headers that are supposed to fit. They go right into the subframe though.. My thought is its the hoakie motor mounts on this thing- they're not where the normal ones are. He fabbed some up so the mount sits literally over the steering rack. So here's a pic of the passenger side that goes right into the subframe, I'm scared to cut out any more since a bunch has been hacked already. Thoughts?? Will it fall apart if I cut that much more out? I'm trying to get this squared away so I can get back on the road. Please help! I'll post pics asap (on phone now).

Hello nnowa07,
I think I can help here, I am assuming you are talking about the Ranger V8 RSO and early Mustang LSO Hedman units. If this is the case then these will NOT fit with your current sub-frame. The build that featured these headers, ( Stein I believe, well worth a read for the true DIY, awesome build ), had extensive mods done to the front K-frame so they would clear. I myself went with the mountless V8 Roadster front frame and used the V8 Ranger Swap kit headers. I had to locate the motor back to within 3/8" of the fire wall and offset the block / tranny center line 1.25" to the passenger side. The drivers header cleared the steering by about 1/8" with the Ranger header, I believe the Mustang header would allow more room here. I just applied a small amount of ball peen love and was able to achieve 3/8" clearance. I believe you will require a set of headers from Martin to fit your application that exit out into the front wheel wells. Defiantly consider a new front frame, that one looks hacked, think safety brother, hate to have it fail at a buck forty!!

Check my build thread for how the Ranger V8 swap headers fit the V8 Roadster frame in my application. 302 NA build:3gears:

Thanks for the reply! I took a gander in your build- looks awesome! Thanks for posting so many pics for the rest of us, I know many will be grateful for the extra time you took to make that happen.
I think I have a solution for mine- I'm going to cut just below the collectors, and put about a 30* bend in and go through the existing hole which should work. Once I get the headers in, I'm going to go through and clean up the subframe and put as much bracing as possible in. Unfortunately I bought the car "completed" thinking I would save money and time.. Well lesson learned. I've bought a new motor, new trans (last one was a t5 from a 4cyl mustang that imploded), new rear end (stock Miata rear end on there), new wiring (a total rats nest), etc etc. When I bought it I didn't know much about the builds so I didn't know what to look for, I guess I figured maybe a hacked subframe was par for the course. :/ it's been a good opportunity for me though at least, this is my first project car really, so I've gotten a lot of experience and learning a ton. I suppose you can't put a price on that.. Although I guess I did. :)

I have built many early Mustangs when younger and never seemed to be the buyer that got a break, LOL. My friends would score all sorts of goodies and I never seemed to be that lucky. I understand your pain, but as you stated in reply, you have learned to look closer. More than happy to post pics, that be the easy part. I have to admit that I did not think fitting a V8 into a Miata was going to be as much work as it is, this has to be one of the most involved car builds for me to date. Wish I could spend more time on the project but my work has kept me very busy over the last 2 years. Good luck on your progress and defiantly don't be afraid to ask questions, I bet a few of the members have already been there done that and always seem happy to help. Great Community

Keep moving forward

Unfortunately I don't have the vehicle any more. I might be able to drum up pictures somewhere. It ended up working out but the clearance was TIGHT. The exhaust shop that I worked with did a decent job for the amount of room he had to work with. Because my car had the stock diff, there was the PPF still on the passenger side, so he Y'd the passenger exhaust over to the driver side just in front of the trans (motor side of the bell housing theres a little dip he used), and T'd into the driver side exhaust and ran a single all the way back. Car sounded great but probably lost power as a result of not running true duals. The shop also tacked the nuts that held the exhaust to the header as there wasn't really room to tighten them well and they wanted to back out. It was a pretty crazy job and I feel for the new owner if he does make any changes! Driver side header fitment worked, but it was tough. If you can, probably best to go with the tried and true Martin setup especially if you're using his kit (i was not and my motor was a slightly different spot from my motor mount positions). Best of luck.