I currently run these: https://www.summitracing.com/nv/parts/hed-35276/overview/year/1968/make/pontiac/model/firebird with copper gaskets and I'm very happy with them. I mated this to a Flowmaster complete exhaust system. I will probably upgrade to Doug's solely for the purpose of going from a 2.5" exhaust to a 3" exhaust to better handle the spent gases from the 474ci I'm currently running (previously Pontiac 350). These headers are short length headers with a ball and socket reducer they tuck up near the subframe which I really like.