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

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

Bummer. It's still a good crank. Just not as good as forged.

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?

Not for the power level you want. Try exhaling through a straw while running. Same scenario.

The 72 and up cylinder head had a 1.88 intake valve, not a 1.92.
Geez. What was I thinking???