I am swapping an 86 305 1pc rear main out for a 70's 350 2pc rear main. My question is, is the flywheel that I have for the 350 the one I use? Thanks.

 

A 153-tooth flexplate is usually better because the starter doesn't sit as far out, getting in the way of headers.

But, if you aren't running headers, the 350 flexplate has the bolt pattern for your torque converter, and you use the correct starter for a 168-tooth flexplate, it'll work.

 

So if I decided I wanted to use the 153-tooth I couldnt use it from the 305 correct? The pattern from the crank to flywheel is different from 1 pc to 2pc, right?

 

Correct. You'd need to get one for the earlier 3rd gen f-body application (like '84 305 auto). But, you could use the 305 starter as long as the block is drilled and tapped for it.

 

I was just thinking about that a few minutes ago. Thats my solution then as my starter is brand new. Thanks five7.