351 cleveland, or 351 modified/400 heads, and a solid cam with a 780cfm holley. Your best bet would to get some later 2v 351c heads with the 2.05/1.65 valves, the earlier ones had huge valves and ports and is simply too big for a little 302. Youll need to drill some holes into the intake sides of the head for a water crossover into the intake manifold. Get a boss 302 intake but be ready to pay 450 buckaroos for one.
boss 302 intake
Keep in mind that this is late late 60s early 70s technology where ford would spin a 302 to 8000rpm to get 400+hp, there is a wide selection of actermarket heads out there that would simply outpower the cleveland heads. You can go out and buy a single plane intake, a healthy cam and some good heads and get 400+ without going much over 6500rpm. Just thought id let you know that theres better heads out there, but then again...they dont have the "cool" factor.