Better heads

I would still preface those numbers with "Your results may vary" Bobby..lol. Your heads, on your car, with you machining, and you tuning, and a car that is a drag race and sorted combo. I also dont feel really great about 207cfm. Good numbers for the valve size and volume surely, but not enough for what I see being considered for the OP's 318, or 1967's 350" engine. I'd rather run a milder cam with a bigger port than a small port. I just get a better result that way on average. My own feeling is the 302s are a bonus in terms of cash outlay and least invasive. But they will limit both combos in the real world of compromises in conditions.