TH350 behind a Big Block
 

... seems to me that would be the weak link in the power train. Why not stick with the tried and true TH400??

I plan on running a 454 and automatic. I have a couple of TH350s on hand and one questionable TH400 out of a truck which I would hate to install and then pull due to the situation that it might be worn out. Is the TH350 a tested replacement?

Any advantages to running the TH350?? All I can think of is negatives.

....... be my guinea pig! LOL

No other responses, well I'll start. Chevy used the 400 behind the big blocks for a reason. That's not to say a properly rebuilt 350 won't hold up but if it's still at stock specs it's not going to take the abuse a 400 will.

If you have a couple of 350's throw one in and see how it holds up. I know it's work installing it but if you have them it won't really cost anything.

Already have a driveshaft?
If so, whats it originally from? PG yoke and D-shaft length will work with a TH350 as is (assuming short tail housing)...the yoke is different for a TH400 and the shaft will be shorter.

Right on the shafts being different .... I think it is spline count? I was thinking of using the 350 stock shaft with a 400 yoke .... if I went with the th400. Is that doable?

Hank maybe I am greedy but I want to learn from someone elses bad expierence! LOL ... swapping trannies is not my favorite chore!

I hear you, I know a there are quite a few 350's running behind some pretty stout motors. They're probably not stock 350's though.

Yeah but you'll have to shorten the driveshaft...about an inch or so.

If given the choice, wouldn't it be money better spent on the more stout trans ?

I know our small block is no slouch but given the choice id choose the TH.

Then this brings up the question of rear ends. Is that the weak link before the trans ?

Dave

This is an older post and may have already finished but here we go.The turbo 350 has advantages.Its easy to find a cheep rebuildable core and cheap to rebuild.Its lighter and reduces your unsprung wheight and uses less power to run which means more power to the wheels.Will handle 500hp all day long.The 400 is stronger but I wouldnt loose any sleep over it.If you have any spare 350s pull it apart and youll see how simple these things realy are.All you have to do is be carfull when putting it back together you dont damage and seals and your golden.