GM B-Body Forum Wed Dec 14, 2022 4:38 pm
Hello there, and welcome to the forum! You have a few options when it comes to headers. The square port doesn't matter as all sbc have square exhaust ports and you can use round tube headers on them. What I've discovered is headers that have primaries larger than 1-5/8" are typically square. 1-5/8" and smaller primaries are usually round. I have Hooker headers 409 stainless steel 1-3/4" long tube headers and they are square port. The part number is 2551-2HKR. They fit our cars but need just a little massaging on i think 2 tubes if i remember correctly. Before that I ran flowtech headers part number 11100FLT (31100FLT is the ceramic coated version) and those had round 1-5/8" primaries and I liked them better actually, only 1 tube needed massaging and changing plugs was easier vs the bigger headers I have now. The hooker headers I have now are less than $300 for the pair, it is 409SS so its not the best but they are a good set of headers.