First let me explain what is happening, 58 tf onto a 91 S 10 frame, extened 6" for proper wheel base,with a 87 s 10 blazer rear end, I have a drive shaft that is 1 1/2 inch shorter than i need, at least i think so. engine is 350 and a 700r4 transmission, with the drive shaft in place the slip collar is into the trans about 1 1/2 inches, but there is still another 1 1/2 inches that in needs to move to put the seal at the proper place and allow movement that it was designed for. the only other thing that i cannot do is compress the frame and springs for the ride height that the truck will set at when completed. if I made myself understood, I am open to any suggestions,