'302' Combustion chamber volume?

Here's what you need to do. Get yourself flat-top zero-deck pistons and mill the heads to get 10.5:1 compression (or more if you want to experiment). Then have ALL of the edges in the combustion chamber radius'd; not just smoothed, but ground into a definite round shape. Also kind of smooth the curve into the squish pad to create a "wedge" effect, and grind down that pointed "ridge" going between the valves. What this does is greatly increase flow across the valves and greatly reduce the tendency for hot-spots to manifest in the chamber. Also, when the flame front begins to move across the chamber, it will take on a true "wedge" shape as it approaches the squish pad area and will force itself into the squish area, leaving much less unburned area on the piston than is common with closed-chamber heads. You won't have to worry about ping and mileage and power will also improve, especially on the low-end (and you won't need to use a high-overlap cam to reduce cylinder pressure).