A TH350 transmission question...

[meanboyjr]

This is a bit off-topic, but I figured if anyone knew, it would be the folks on this board.

I'm currently working on a hot rod project, into which I want to drop a 350/350 combo. A buddy of mine has a '77 K5 that is a rusted-out pile. He would give me the engine and trans out of the K5 for free (can't beat the price), since he's probably going to scrap out most of the truck.

I'm thinking that the only way to use the 4wd TH350 in the 2wd project is to 1) get a new tailshaft housing and then 2) swap in the appropriate 6", 9" or 12" output shaft. I'm pretty sure this means taking the trans apart myself to do the swap, or sending it to a shop.

Am I right in thinking this, or is it more complicated than that?

 

[diesel4me]

Far as I know what you stated is accurate...GM made only one length TH350 ,then swapped the tailshaft and housing to use it in 4x4's or cars..ditto for the TH400 too..

You "could" leave the transfer case on the TH350 and just use a shorter rear drive shaft too.....but that would be too tempting to keep going and make the 2WD a 4x4!..

 

[meanboyjr]

Far as I know what you stated is accurate...GM made only one length TH350 ,then swapped the tailshaft and housing to use it in 4x4's or cars..ditto for the TH400 too..

You "could" leave the transfer case on the TH350 and just use a shorter rear drive shaft too.....but that would be too tempting to keep going and make the 2WD a 4x4!..

I finally bought myself a "hot rod" truck, which will remain 2wd...for now.

Thanks for the info. I'm still pretty sure the whole trans has to come apart to swap output shafts.

 

[dyeager535]

It does. Output shaft comes out the front.

 

[diesel4me]

In a perfect world,GM would have made the output shaft removable from the rear instead...sure would be sweet to buy any TH350 or TH400 and be able to swap whatever output shaft into it you need without removing and gutting the entire transmission...

They could have at least used a typical "short tail" transmission used in cars and 2wd trucks ,instead of making a "special" super short output shaft..the only time they got it right was in the early 80's,when some TH400's with a NP-205 used the same length output shaft as a short tailed 2WD version..

Makes no sense to me why they made so many different output shafts and transfer case adapters..they say tooling costs are expensive,they sure didn't care about that when it came to their 4WD drive trains I guess ..