what's in that 340?

I am basically thinking of a 400 to 500 horse motor. I can buy a crate motor with all upgrades from Indy for a 408 stroker with about 465 hp For about $7500. I already have a 72 340 block only bored over .030 and was thinking it would be cheaper to build the 340 plus cooler for the duster. Opinions are welcomed. Again street, show car and maybe some strip for fun. I don't have a track close so once a year probably be the norm.