7 1/4 Vs 8 1/4

Been awhile since I checked this thread, thanks for the input guys. I picked up the rear end last weekend (blowing out my back in the process;-) All I got was the rear end, now I will need to dig up shock plates and u-bolts as I did not get them. Shortening the driveline, no big deal. I unloaded the rear end from my pickup by myself and now my back hurts so bad I can't work on the car. Hoping to heal soon. I know the rear end is from a 74 Duster and is a 3:21 SG so I have high hopes!
Rat