Alright i will start out with this the cats are clogged on my truck. I am looking to replace both cats and the headers i have my eyes set on the pacesetter

My question is if i run long tubes which catalytic converters would match up best with those headers and the exhaust is no longer stock its the Corsa sport cat back. Id also like to keep the cats strickly for emissions they use a mirror to check for cats

And any future upgrades may be a xr265 cam. But would be a way down the road. I am just looking for any advice on this engine and builds anyone has done.