64 barracuda 273
Use the 273 with the 318 heads and the "67" 273 4 barrel intake. You need the 318 heads to use the 66 up intake manifold. You can always mill the 318 heads to get the compression you want. Run the Commando exhaust or clone it. Easy to get 265 hp out of a 273 with 2 barrel pistons, a small .425 lift cam and 340 valve springs. Nothing else needed, trans works, rear works.