318 engine combination

I think you're on the right track. The 1.88/1.60 valves in the 302 heads work well, especially if your head shop does a nice deep 70 degree bowl cut and you follow up with a basic blend and gasket match port job. Nothing cosmic, in fact Mopar sold this exact setup over the counter in the early 90's. A 30 degree back cut on the intakes help.

So long as you have a halfway decent exhaust system you should end up with an honest 300 hp at the wheels.