Thanks a bunch Pugsy!!! I think you just gave me everything I need.
What I will be doing is putting a 700R4 into a 79 with an 8FT bed that currently Has a TH400, 2 Piece Driveshaft, and a 12-bolt Rear. Trying to do it with existing parts and not cut or lengthen any shafts.
What I am trying to figure out is if all I need to put a 700R4 in the 79 and keep the 12 Bolt Rear end is the front driveshaft section from either a 8FT Bed 700R4 Truck or a 8FT Bed TH350 with 9" Tailshaft truck, or if I need to get both front and rear pieces from a Pre-82 9" Tail TH350 12 Bolt Axle 8FT bed truck.
In looking at the interchanges it looks like the rear sections for 8FT Bed 12 Bolt Trucks (Up to 81) are the same for the TH400 and TH350. It also looks like the Front sections for the 8FT bed trucks with a 700R4 or 9" Tail TH350 are the same from 77-87. I
get into the interchange stuff at length here.If I am looking at these two pictures below correctly than the rear section on yours measures about 34.5" Weld to weld, correct??


I just measured mine and it's 34.5" weld to weld. From the rear weld to the rubber bushing on the driveshaft bearing it's 45".
So far it's looking like the rear sections on the 12 Bolt Axle 8FT bed trucks are the same. So all I will need is the front. The interchange for the rear section on your 76 pulls up shafts from trucks all the way to 81, and the front section pulls up truck up to 77 so still not sure, because a search for a front section for an 85 brings up parts from trucks back to 75. So it seems there is allot of overlap and if the measurements are right it should work.
Would you mind grabbing the the measurement on yours from the From the rear weld to the rubber bushing on the driveshaft bearing when you get a chance.
Thanks a bunch!!
Edited by: Ziptar at: 3/11/06 3:58 pm