Hi all,

I finally swapped out my 7 1/4 rear for the 8 1/4 in my 72' duster. After measuring, the driveshaft needed to be cut 2 1/4 inches in case anyone else is going through the same process on there duster.
My question is this..
Does anyone know what the correct size screw is, that holds the driveshaft to the 8 1/4 rear yolk. I tried using the same screws from the 7 1/4, in the 8 1/4 but they seem to bind after 1 or 2 turns.
Even though the holes look clean, it could just be dirt or some rust that's causing this, but i just want to make sure.
Thanks

Are you sure on the 2.25 inches? That's the same amount you need to shorten for a 8.75 and I didn't think 8.75 and 8.25 cars could use the same shaft.

Yes, the bolts that hold the yoke straps on, that retain the U joint should be 1/4-28 Fine thread on both. If the 8-1/4 has been sitting a while the threads are probably rusted. On the driveshaft shortening deal, I just put an 8-1/4 in place of a 7-1/4 in a Dakota (brother in law's truck, used to be mine) and I had the driveshaft cut on that one, either 2 or 2-1/2. Rememeber that cutting the shaft 1/4" shorter than needed won't hurt a thing, (thats what the slide in yoke is for) but too long can cause problems if the yoke bottoms against the output shaft.

Thanks for the replies..
I'll go pick up some liquid wrench, a tap, and get er done!