Who is useing Header extensions?

Also back pressure is never a good idea.......if back pressure help your ride, it is because you hit the tuned length that the eng wants.
And if it slowed.....you probably need to jet it a little. This i have done when i was running a full exhaust and would un bolt at the collector, at the track.

With pipe max it said, that i hit the tuned length at 16.7 inch and then next one was at something like 58 inch and the 3d length one was longer than my car:D

Remember, this is like losing 10 pound off of your car........not going to see much difference in et. But it you can find 10 more placed to remove 10 pound Now, you have improved your ET by a tenth. The colector is just 10 pound............