I had a set and loved them,They didn't have to be machined out to fit my ported heads the uppipes where 2 inch the bad part is they wouldn't clear my down pipe but I found out after I sold them that Tony Burkhardts stainless down will clear them I wish I still had them they were very nice manifolds and uppipes.I sold them to Eric (Wisconsonhick1) and he loves them,he just squished his down pipe to fit.