I thought this would be simple enough. Aparrently not. Back in the days of "D" port heads, I used Hedman headers on my 1967 Firebird. Perfect fit! The new motor has round port heads. What are you guys using these days? (67-68 bird w/round ports) I cant seem to find any headers with large primary tubes for a high HP application. I looked at Hooker & Headman. Am I missing something?