For my Challenge car I'm using a GM TH350 transmission. Because of where I've located the steering rack in relation to the engine block, every dimension from the rack to the rear end is dictated by the length of the components I'm using. The wheelbase is 93 inches and it would be handy if I could reduce it by an inch, but I can't move the motor mounts or shorten the drive shaft. So, my question is, what does the transmission yoke bottom out on? The end of the splined shaft, or the end of the yoke hitting something inside? Can the yoke be chopped off by an inch or less and then go in further?
Typically its the Yoke bottoming out on the shaft at the U Joint end. Also typically you'll have the un-machined section of yoke hitting the seal before that happens. I just went through this with a driveshaft that was too long on a manual trans but the auto should be the same.
If it does bottom out the freeze plug pops out as a safety measure. (splines cut all the way through yoke) Or at least mine was
In reply to asphalt_gundam :
Oh, I never realized there's a plug in it. I'll have to go look closer. Thanks.
FWIW, the output shaft can be chopped down an inch if you're particularly brave. 
Won't help with seal clearance but will make a cool photo on the internet.
In reply to Tom Suddard :
Have you been brave enough to do this mod?
+1 on yoke hitting the seal first, with stock length yokes. BTDT on a project car that the driveshaft shop screwed up the math on making a driveshaft for it.
