How much power can the stock tpi flexplate handle? I want to drop in a 400 hp 383 tpi motor in my 91 z28 and i'm trying to save a few bucks.

 

It'll handle 400 HP easily enough.

Is your 383 internally balanced one-piece rear main seal?

 

one piece rear main seal, i says on their site it's a balanced rotating assembly. I don't know if that means internal or external.

 

I had a stock replacement flex plate from pioneer and it cracked 3/4's of the way around the crankshaft the first time I jumped on it from a dig. I am making alittle more than 400 but not like 500 or anything. A good SFI approved plate is pretty cheap insurance against dropping the trans a second time.

 

You need to know that. If it uses a stock type neutrally balanced damper, you can use a stock type balanced flexplate.

I'd have to agree, though, that $65 in a 383 budget doesn't seem excessive, especially for the peace of mind you get for it.