i wish i could tell you, I have mac longtubes also and was looking for an x pipe that matched with the lt's but no place offered PERFECT fitment, only 'maybes', i didnt wanna get anything welded, vrs x pipes supposedly matched up, dont think they make h pipes though, call bbk up and ask them, or call mac and ask them, or u could be the guinea pig and try it out and let us know? lol good luck