The best stroker 408-416-426-435 combination in stock 68 340 block

While not perfect, the CNC work from Hughes will move enough air to do what the OP wants provided all the parts work together. He doesn't need every last cfm of flow. There's enough cross section for a 500-550hp engine needs with a street/strip type setup. But the numbers Hughes posts are usually not reality anywhere but at Hughes... So unless you're racing there, I would have somewhere else simply flow test them. Not to improve, just to get more than the baseline supplied numbers. Then you can better decide on a camshaft package.