I run the Hedman 65101 headers on my 69. 1-3/4, 3" collector. The fit is pretty good. The thing I like best about them is the gasketless ball and socket flange they come with, much better than the leak prone standard header flange that most headers use. Spark plug access to 5, 6 ,7 & 8 is not great, easier to get these from under the car. Had to build a special spark plug socket for this. Could be my heads too, Pro Topline 220's. The spark plugs are angled differently than stock SBC heads. Oil filter access is a bit tight as well. My wide sump pan doesn't help matters though. The only part that needed clearancing was at the lower control arm bolts and spark plug #1. Depending on your heads, spark plug #1 might not be an issue.
