My son and I made a project of installing a set of Mac headers on his 95 Z28 this weekend ... He is home for Spring Vacation from college and this was an opportunity to spend some quality time ... We got them installed ( some 20 hrs later ) including new plugs and wires ... The problem we encountered is that while the original exhaust manifolds mount points had an inner lip that the airtube compressed against, the receptacles on the headers are totally hollow so that the air tubes never really get tight and they leak. I am thinking that maybe I could screw some kind of hollow plug into the tubes to create a compression point so that the airtubes will seal. However, if someone has a better idea, or, know of something thah already exist explicity to address this problem, please let me know. Hey, it was fun weekend, but, I am am glad that I have only 1 son ... My hands do not want to do this again any time soon ... Thanks in advance .... Steven Sr.