Well I am going to be putting on my SLP Longtubes on sat but I am keeping the stock SLP centre exhaust on the SS. Well now I am not sure what will fit, the intermediate pipe on the SS exhaust is it 3" or 2.5" because I think the y-pipe that came with my SLP LTs are 3"....correct?? I don't wanna tear apart the cara nd find a problem with sizes? So will the SLP y-pipe fit up to the SLP centre exhaust??

 

it should fit

 

I had that same set up for a while on my 01. The centermount exhaust is 3" & it will all work fine with the headers.