you didn't give enough info ..... but this is what I know, 440=under 10mpg ANY way you build it. But the most power for gasoline. 318 stroker? why bother . 360 best small block. I run an 1989 cummins 5.9 diesel good milage good power awesome reliability low maintance. I also understand you want to use what you have on hand. that's my 2 cents.

71 challenger convertable, 64 sport fury 383 ci with factory air 99 sebring convertable 89 CTD pup