Engine/tranny placement vs driveshaft
 

Some of the threads I read where folks are leaving off the air tube at the back of the engine to be able to slide the engine back a bit further. Does that affect the driveshaft length? Martins manual says 30.5" center to center of universals, so wondering if a shorter one is needed if as I plan on not using the air tube.
I'd like to get a driveshaft ordered, the plan being to have ALL my parts ready to decrease downtime.

I deleted the air tube on mine. When I purchased my kit, the driveshaft was included. I had to have the driveshaft shortened. I cannot remember how much.

If you want to save a little money, I would suggest getting a used shaft from the junkyard. It can be sourced from many different Ford models as long as the yoke will fit your transmission. An aluminum shaft can even be found if you want to go that route. I believe they were in a lot of Areostar vans. Check with a few of your local car dealers & repair places for a recommendation on who they use for driveshaft repair. Bring the WELL CLEANED driveshaft to them to be shortened, balanced, & new u-joints installed. Most good shops can have it back to you the same day.

Driveshaft length and pinion angle are pretty important. Not something you're going to have to guess at. Once you get the engine and trans in place, take some very careful measurements, and order what you actually mean. If you order it the same day you bolt the engine in place, you'll probably have it before you're ready to fire the engine.