1977 3/4 ton driveshafts

[two77silverados]

A while back I bought a 1977 Silverado 3/4 ton Camper Special missing the original 454 engine, TH400 trans, driveshaft and several other parts. I've been slowly piecing it back together to be a cool tow rig. I already found a 454 engine and TH400 trans but I still need a driveshaft. Today I spotted a 78 3/4 ton at a salvage yard but it has a 4-speed manual transmission. Will the driveshaft from the manual trans fit my TH400? Do they have the same yoke and are they the same length? I'm guessing they are different. 

[Captkaos]

In general I don't look for driveshafts.  If I need one I just get one built. 

A pre 88 sm465 will have a 35 spline output on a 2wd.
A TH400 has a 32 spline and it could be a fixed yoke or slip yoke.

Chris Lucas
73-87chevytrucks.com
captkaoscustoms.com
squarebody.biz

[roger97338]

In general I don't look for driveshafts.  If I need one I just get one built. 

Chris Lucas
73-87chevytrucks.com
captkaoscustoms.com
squarebody.biz

Captkaos, when you're replacing a drive shaft that originally had a carrier bearing, do you replace it with one that also has the carrier bearing? Or do you have a one-piece shaft made?

[Irish_Alley]

you can go either way. there is a length limit to the shafts but i want to say its 70+" gm put 2 piece on some trucks and i still dont think to this day we know why. i had a one piece on my 86. changed transmissions th350 long to th350 short went into a bone yard at dads work took a two piece that was the same length as my one piece and made it work by dropping the bearing down making the shaft longer. that two piece also came from a gm with a different trans. supposedly two piece are stronger but you will have the same argument if you ask someone who make one piece shafts

[bake74]

In general I don't look for driveshafts.  If I need one I just get one built. 

Chris Lucas
73-87chevytrucks.com
captkaoscustoms.com
squarebody.biz

Captkaos, when you're replacing a drive shaft that originally had a carrier bearing, do you replace it with one that also has the carrier bearing? Or do you have a one-piece shaft made?

     The 2 piece shafts were used mainly to get them to balance.  The longer drive shafts can be problematic with balancing.  Second reason was on bigger trucks the torque required to make truck move sometimes was too much for a single long drive shaft to handle.