The only differance is the disk, he has the 14 spline T5, which he did use the '86 4.3 astro van 11" clutch disk.
I knew it needed to be spaced back, I didn't know if the belhousing was longer or not on the 4.3 for the tranny. I know the GM tranny's are the same bolt pattern. I just never put a T5 in anything different then stock.

Other than the spline teeth (Just use a different disk), and that the shifter is in a different location (Just switch the tail housing to move the shifter), the Mustang's tranny's interchange!

Hell, I have a GM pressure plate with a 11" disk that bolts up to my stock Hemi flywheel, and I have a GM tranny behind my Chrysler Hemi & a Ford 9" posi behind that.

Pat