I bought a used 3" dia shaft from a later camaro. Went to the driveline shop to have it balanced w/new u-joints and installed. Driveline shop said the alum shaft was 3/4" shorter between u-joints and didnt want to doe the swap - moves the joint to far back and loads the tailshaft too much. U can read elsewhere this swap is done all the time. Im wondering if anyone here noticed this. I will verify length once i get both d/s out on the floor.