what needs to be changed in a 72 340 to be like a 70 340?

340plot said
the block is a 2/9/72, but the damper says on it that "use with a cast crank only"

i really have never had any luck with headers, and i will not put out that kind of money for tti's. so will i be ok with the stock 72 340 manifolds?

I doubt it. You'll need a good header with a 1.75 primary tube.

The 72 and up cylinder head had a 1.88 intake valve, not a 1.92.