318, 383 or other? Which one

better power per dollar
get a 440 / eddy heads / the right pistons for your gas

or a 400 stroked out to a 451. the 400 will give you a little more space under the hood

you will need to get a kit to mount the big block in there, and your rear will need to be solid and the right springs / tires / etc so you hook

you will walk all over most any camaro.

i know a guy with a 7 second one however... be careful what's under their hood