I just replace the 7 1/4 rear end with a 8 3/4. I have a 70 Barracuda, 360 with a 727 trans. It looks like I need to shorten the drive shaft. Does anyone have the specs for the length of the drive shaft? I'm going to measure it but I want to be sure I'm within specs. Thanks.
info here .. https://forum.e-bodies.org/engine-transmission-and-rear-end/4/driveshaft-length/9638/msg133569#msg133569
Bottom out the yoke in the trans, then pull it out 3/4". Now measure the length you need.(center of u-joint to center of u-joint)
This should be obvious but make sure the rear end is supporting the car's weight when you measure. The rear end can't be hanging down with jack stands on the body.
That's good to know. Some where I read to measure from the trans rear seal to the center of the rear U joint bearing. I guess that will achieve the same thing.