crew cab rear driveshaft HELP

[papapavs1]

I recently purchased a 76 chevy c20 crew cab longbed, 350 with automatic trans. rear driveshaft was out, supposedly for being flat towed many years back. There were two identical driveshafts laying in the back, around 55" each. Well turns out they're completely wrong, way too short and different splines. I counted 32 splines on the front driveshaft, and about 65" of length needed for the rear driveshaft to work. I measured the rear driveshaft on a 78 gmc cab and chassis (longer wheelbase) and it looked to be 65 inches, couldn't see the spline count as it was still on the truck. My question is, Has anybody ever had anything similar before? Will a cab and chassis driveshaft be the same/work? Or else where have you guys gotten your driveshafts for these?

 

[squaredeal91]

If you get one that fits at each end correctly but is too long you can shorten it up to perfect length

 

[Ricko1966]

I recently purchased a 76 chevy c20 crew cab longbed, 350 with automatic trans. rear driveshaft was out, supposedly for being flat towed many years back. There were two identical driveshafts laying in the back, around 55" each. Well turns out they're completely wrong, way too short and different splines. I counted 32 splines on the front driveshaft, and about 65" of length needed for the rear driveshaft to work. I measured the rear driveshaft on a 78 gmc cab and chassis (longer wheelbase) and it looked to be 65 inches, couldn't see the spline count as it was still on the truck. My question is, Has anybody ever had anything similar before? Will a cab and chassis driveshaft be the same/work? Or else where have you guys gotten your driveshafts for these?

If the 65 inch shaft comes out of a car or truck with a 700r4 or th350 it will be fine. Even if it doesn't you can swap the front yoke. You may or may not need an oddball rear ujoint,but that's no big deal. When I need a different driveshaft. I don't even pay attention to what it comes out of. I go to the bone yard with a tape measure,find something the right length,and deal with the yoke and ujoint.And a little short isn't goingbto hurt anything it doesn't need to be dead nuts 65 inches.

 

[squaredeal91]

If the 65 inch shaft comes out of a car or truck with a 700r4 or th350 it will be fine. Even if it doesn't you can swap the front yoke. You may or may not need an oddball rear ujoint,but that's no big deal. When I need a different driveshaft. I don't even pay attention to what it comes out of. I go to the bone yard with a tape measure,find something the right length,and deal with the yoke and ujoint.And a little short isn't goingbto hurt anything it doesn't need to be dead nuts 65 inches.

Good advice, I've got 3 driveshafts in 2 rigs with a conversion u-joint. I keep box labels in glove box.