Speed Engineering long tubes and axle dump exhaust

[Bald_Eagle_Machine]

Has anyone bought the Speed engineering long tubes and axle dump exhaust and installed it on an avalanche? I messaged the company and they state that the full size / extra cab Silverado /Tahoe part #'s will fit a 4x4 avalanche. At only $260 for the headers and $450 for full exhaust it seems like a great deal. Wondering how bad deleting the Cats would make my truck run, as they state it will throw a check engine light. Does anybody have experience with this kit, or anything from speed engineering?

 

[enoniam]

I'm running the speed engineering long tube headers and their true dual 3" exhaust kit for a Silverado on my AV.  A local muffler shop tweaked the Silverado exhaust kit to better fit the AV.  My only gripe with it is it makes dropping the tranny pan, or the entire tranny, a bigger pain than it should be.  I keep telling myself that I should have the muffler shop put some v-band clamps on the "y-pipes" section to make getting that section reinstalled not require practically removing the rest of the system.  If you were to dump at the axle that would make it a bit easier to do that, and may not require any tweaking.  I've got my twin pipes exiting at the stock position behind the rear tire on the passenger side.

I don't know how much performance you will pick up - it depends upon how hard you are pushing your existing system.  I felt that my JBA shorties and Flowmaster muffler were holding my 460 hp crate motor (plus supercharger) back.  That feeling was confirmed when I dropped a half second in the 1/4, going from high to low 13s.