This is probably a dumb question, but can i use a th350 with a 400 smallbloc? Will I have to do anything or do they just match up. The 6 anger is dead. Had it for a week, and It needs a new crank, thekeyway got eatin all up an destroyed when something happened with my harmonic balancer. So i decided to go bigger. Found a 500hp 400sbc for 1500 dollars.

 

Just have to change out the flexplate to one that is extenally balanced, to match the 400. Will physically bolt right up.

 

If you are tight on money you can use the current flexplate and buy a balancing plate. I would by the new flexplate myself, but just thought I'd throw the other option out there for you.

 

It will bolt up, but don't know how long it will live. Especially if 6 cyl application th350's aren't built as strong as V8 TH350's (don't know). I have a TH350 behind my 400, but it had a performance rebuild done, and my engine doesn't make 500hp.

 

the trans was just rebui;t 3 moths ago, and is built for a V8

 

I ran a TH350 behind a 12 sec 350 w/a 10" converter and 4.11 gears for over 10 years w/out any probs.

 

a starndard rebuilt tranny wont hold up to the abuse a 500 hp sbc is gonna give out buy the 400 wait a little while longer and get a tranny to handle the abuse


i have a friend that has a fastburn 406 that has been through 4 or 5 standard rebuilt 700r4s

 

well, in some cases, 700Rs can't take the abuse of a stock motor... Now stock TH400s I hear are pretty strong, my buddy has one behind a ZZ502 in a chevelle, but he doesn't drive it much.