I have Stainless Works (or Worx) hearders with 3" collectors that are mated to generic 3" cats, then to some bastardized 3" center section made up of pipes between the cats and x-pipe and more pipes after the x pipe that have 3" to 2.5" adapters to mate to the over the axle exhaust which is a 2.5" Corsa Sport. It has never fit right and hit the frame in a few places and hits the bottom of the tranny but I have lived with it. When I did my clutch a few weekends ago I managed to seperate all the pieces. The cat material disintegrated because of all the banging it took to get everything apart but I put things back together as best I could get it to go but it still doesn't fit right being as it's "custom". Mostly because it doesn't exit in the correct position where the over the axle mates to it so the right over the axle pipe still hits the frame. So now it sounds crappy and smells due to no cats (although power is notably increased). So I want to replace everything from headers to axle. I'd like to keep it 3" but I want it to fit as ~factory as possible.

I've narrowed it down to the Corsa 3" center section P/N 14173 which is made for a Z. http://www.corsaperf.com/product_loc...?product=14173 And the Corsa 2.5" center section that would bolt up to a stock coupe, p/n 14163 http://www.corsaperf.com/product_loc...?product=14163

I can't see there being any difference in the bends between the two; seems like the tranny in the Z would be in the same place as mine. Both of these are one piece (albeit no cats) and look like the best options for me. I would prefer to stay with 3", I could weld up the 3" to 2.5" adapters that are on my existing pipes but I would have to make sure they exit in the same position. Even if I go with 2.5" I would have to neck it down from the 3" collectors. I'm undecided about putting cats back in as of yet.

I guess I'm looking to find out what others have done in cases like this.