318 Mopar vs. 340 Mopar

I want to build a high-compression 360 Magnum for my '70 Duster in the future. Iron Ram Magnum heads (home-worked), flat-top zero-deck slugs (10.5:1 comp.), Lunati Voodoo cam, and other goodies, hooked to a Passon A-833 OD and an 8-1/4" rear. Of course you could go with something milder, but 360's are fantastic motors no matter what you do.