Hey. Just wandering if anyone here has used mac mid length headers on an LT1. I would just go with long tubes but I am not really sure of my emissions requirements, so I was looking at these. Mac's site says something like up to 28 extra hp to the wheels over the stock manifolds. If you have any opinions, let me know.

 

you can go with longtubes and pass emissions, but you will have to make a technically "illegal" modification and move or replace your stock cat. I'm actually in the process of doing this now(LT headers and Y pipe are on the way in the mail). As far as the Mac headers go, I have not really read much about them, but I doubt the 28 wheel HP over the stock manifolds.