I have pacesetter headers, pacesetter y-pipe, and a magnaflow catback with electric cut out. I bought some used TSP cats because of emissions and the inspection around here is a pain. Where abouts should they be welded in on the y-pipe, car is a 00 ls1 btw. Thanks

 

You'll want to get the cats as close to the header collectors as possible, but also being careful of any fuel/brake lines or underbody components that may be in the way.

 

thanks