I'm in the middle of a similar project. Mine is a swap over from a 904 to an A833, however my 833 is out of a 65 A body. The big dilemma for me was getting the right bellhousing. #2468433. I tried to adapt an aluminum bellhousing, but "no-way-Jose'" way too much needed modification. My application uses the same fork as the three speed and the input shaft of the 833 poses no problems. I'm waiting now for some new pressure plate bolts I ordered to install my Zoom scalloped, 10" clutch. 1965 Barracuda tricked out 225 /6.
Norm