If it was my car I would stick with the flat head. I'd shave the head a little bit to bump compression then have it ceramic caoted so ir would look like aluminum. Get a dual car intake and dual outlet exhaust manifold. Send your cam to crower and they will grind you a custom one for like 200. For the body, I'd leave it stock appearing maybe a 2 tone job like seafoam with a white top. Run some chrome steelies without caps with some wide whites. Lower the front like 2-3inches and the rear an inch less than the front. I think that would be a bad ass cruiser.