Drive shaft for LONGBED, TH350 Conversion??
 

I have a lonbed and put in a TH350 with a 9 inch tailshaft. Does anyone know off hand what size driveshaft I will now need? It will obviously have to be shortened. I thought someone has already done this ......By the way how do I measure what size driveshaft I need?

Re: Drive shaft for LONGBED, TH350 Conversion??
 

R U staying with the 2 piece or going one piece? I stayed with the 2- piece and ended up cutting 4 3/4 inches off of the front one. But I am sure yours will be different. The best thing to do would be to contact the drive shaft shop that is going to cut the shaft for you and ask them how they want it measured. Here is a thread that may help-
http://67-72chevytrucks.com/vboard/s....php?p=3511906

Re: Drive shaft for LONGBED, TH350 Conversion??
 

I changed manual transmissions once and the shop told me exactly how they wanted it measured and they cut it and balanced very reasonably.

Re: Drive shaft for LONGBED, TH350 Conversion??
 

I recently converted a customer's C10 from a SM420, 4-speed & 2-piece drive shaft & carrier bearing, to a factory 3-speed Turbo HydraMatic with a single piece drive shaft and also eliminated the carrier bearing. I had a new shaft built to accept the slip yoke on the THM and the factory GM 12-bolt. Due to the increase length of a single shaft, versus a 2-piece, the new one was over 3" diameter, to keep it from coming apart at rpm. I paid $160.00, including entirely new shaft, U-joints, balancing and a fresh coat of undercarriage black paint...all in about 3 days.

Re: Drive shaft for LONGBED, TH350 Conversion??
 

LILRED,
How did that 3 inch driveshaft fit in the round circle in the rear crossmember?

Re: Drive shaft for LONGBED, TH350 Conversion??
 

Here if you take them your driveshaft they charge 150 to fit a new one for ya