Driveshaft - 904 to A833 and 8 3/4

no no no

A body 4 spd's are the same length as 904 auto's, however the slip yolk on an a body 4 spd is the larger 727 auto type, depending upon what year, say if it's really early slip yolk style..some will argue that it could have the smaller 904 slip yolk.fyi

Now the 8 3/4 will need a shorter drive line than one from a 7 1/4, if going into the same car as the 7 1/4 was.