well, i have a dilemma.  a while back, my driveshaft for my '83 Sierra 4x4 SWB got damaged and i haven't had time to get it fixed.  well, the guy i'm trading with wants to drive the '78 Jimmy up to me and take the Sierra, but i haven't got the driveshaft fixed...so i had a crazy idea.  i need to know if the rear driveshafts are interchangeable between the two trucks?  the Jimmy has a Th350/203 combo and the Sierra has a 700R4/208 combo...i would like to have him drive up here and us just switch drivelines so he can drive back and i can just have my driveshaft repaired and put in the Jimmy later...i don't think it will work but then again, i don't know and i figured it wouldn't hurt to ask...thanks in advance!