Extreme toploader help--Dhearne et el

Over the winter I want to update my SBF toploader to big block specs. I am going to use the 1 3/8" wide ratio "long" input shaft, the appropriate bearing and the throwout bearing snout. I pretty much have the front covered and I am fairly knowledgeable about the toploader workings. I am also familiar with David Kee's wonderful toploader website.

My question concerns the tailshaft housing needed to install the new 31 spline output shaft. I currently have the C4ZR Mustang tailshaft housing that was used in most 64-73 SBF Mustangs--Rear shifter and 14" long. Do I need to purchase a different tailshaft housing in order to swap to the 31 spline shaft??? Is this as simple as a bushing swap or will I be buying another housing? Can I machine my housing so that the bushing and seal will fit?

HP +stick shift + drag slicks = an expensive pile of scrap

OK, thanks guys. I too have had and built ots of toploaders, but all of them were SBF or 390 based. I do believe that it probably takes a different tail housing, but was confused in that the forward shifted BB housings that were mentioned used the same casing #'s for both 28 and 31 splines.

I've reached the point with my car where it is time to upgrade the both the SB tranny and the rear. In the last 2 weekends at the track I've done this to my toploader:



And this to my 31 spline 9" rear:





Luckily I had another input shaft on hand and that was a quick cheap (and probably temporary) repair.

I since replaced the axles and the True Trac with 33 spline Moser stuff--including a spool so I should have that beefed up enough for the time being. I also got the new axles lengthened so that they take advantage of using more of the splines.