I redone mine once, had the four speed with Patricks 355 ring pinion, their modified four speed sagnaw... drove that sucker for about eight yrs with the enclosed tube.......then one day
I popped the clutch on an incline with a driver about a foot behind me,heard a pop and the truck would not moved...towed it home and appeared the the u joint was the problem.. I replaced it, took a while because I had it in the street, by my self and
me not being a mechanic, got er done... took it for a test drive and all was sweet... I was so proud of myself..........next day
I was driving to work and ever thing came unglued....finally got to work and limped home in second gear...............
I decided it was time to install s-10 five speed, local shop did the work.......... imagine that.lol......best decision I ever made.. almost double the gas mileage... a lot lower rpm at 70 or how ever fast I wanted to drive it........I am sure you will have better luck then I did....
the shop guy said the u joints looked ok... so guess the problem must have been in the rear end, replaced that booger with a blazer...