sorry about the non thirdgen but at least its a gm...

I am planning on putting the 502HP - 567ft-lb crate gm motor in my 81 chevy k-10 4x4 and I need to know what kind of trans I should look for for durability here.

could I get away with a th 350 or would it just blow up?

the truck has 31" tires and stock axle ratios which I have yet to determine what they are.

I will only be doing the occasional cruising and towing and the like with this truck -- no off roading or mudding and surely no dragstrip time!!!

THanks

James

 

You can't go wrong with the tried and true TH 400. With a little prep work it should definitely hold out!

 

Well I would consider your real options to be a 4L80E or TH-400. With a big pocket book you could get a 700R4 or TH-350 to work reliably but this is what the TH-400 design was born for. A nicely rebuilt TH-400 or 4L80E would hold up fine. Considering the extra costs of the computer system the 4L80E would probably be second highest in cost next to the 700R4. I have an 86 with a well worked over 454 and I am running a TH-400 in it with no problems. The main transmission upgrades are the HD sprag (already had it), a kit that included name brand HD clutches, and a shift kit. The TH-400 is the most practical option since it was even available in that truck. Not counting the rebuild it cost me about $300 for a good TH-400 and a matching transfer case. Now transfer cases are a whole different headache but not an area I an overly experienced with. I simply don't push the truck hard in 4 wheel drive. I imagine that if you want to beat on it in 4 wheel drive you will need an aftermarket transfer case.

 

thanks guys..