[radz28]

I've run two sets of QTPs on my car ('02 LS1) and installed a set on my brother's '02. I started with MAC mids', and went with the standard QTPs later with their cat'd Y-pipe. Later, I moved into their newer HVMCs. I picked up more than 10 RWHP with just the HVMCs. However, the Y-pipe, though it was probably the best flowing Y-pipe at the time because of it's tube size and true, Flowmaster merge collector, was a real bugger for ground clearance. The driver's side cat' hung really low. Eventually, I switched to different cats', and moved them both right off the collectors and after I trimmed a little of the floor pan brace above the driver's side cat', ground clearance was A LOT better.

The quality of the materials of the all three QTPs were EXCELLENT. The fitment of my first set of standard collector QTPs were EXCELLENT as well as the quality of the workmanship. That kinda' changed with my brother's HVMCs and mine. He had a really bad collector that wasn't welded completely around the merge spike, and mine wasn't much better. Otherwise, they were very good. Were it not for the complicated merge collectors, I'd give those QTPs the highest marks, but I can't.

If you're working on a 4th Gen, you can go wrong with Kooks or ARH. ARH has standard HVMC collectors and I believe Kooks has a standard collector they say is HVMC, but really isn't, IMO. At the time, they had optional TRUE HVMC collectors, which I would say to go for. I like ARH's Y-pipe a little better because I always though Kook's merge wasn't that clean, but both have great quality, ground clearance, and great materials. Dynatechs were good, but I never liked their small Y-pipes, but clearance and quality were certainly on par with the others.