I say if you want natural aspirated power go big block 400 or 440, if you want to turbo/super charger go Gen III. You can get Gen3 from a reasonable salvage yard for 2.5k wish with engine harness (truck style intake ). I saw a resent magazine article where they compared the truck, 5.7, and 6.1. Ironically the truck intake owned the other 2. If you could make the accessory bracket work you'd save a wadd and still make great power.