The cylinder head is the hardest part to get what you need out of the poly 318. A fella on the B body forum, FBBO, did some amazing work on the poly head so worth taking notes on and asking for his help.
The head design itself is very good and IMO, something that could have been worthy to look into for further performance. It’s a bummer that there were no performance Poly heads ever built. What amazing things could have been done in aluminum?