I see that you have had extensive experience with the various heads and the performance factor on each individual design. I’m looking to upgrade the N47 head on my 78 280z. I’m in the early stages of putting together a build for a replacement engine for the future. Presently I’ve acquired a P79, and P90A head. Other than the round versus square ports what would be your advice on which head to use. Pros and Cons. If you have a moment I’d really appreciate your opinion. Thanks... John