Bad cats options?

[Duramax05blk]

reading on pass side at an idle.
reading on pass side at about 1500rpms, snap on electric impact hammer and a brick as close to 2k as I could get haha.
This is a 2003 denali 168k one broken manifold bolt on both sides. My question is what's best way to go forward, it is the wife's truck. Personally, I want to dmax it but funds aren't there at the moment. So I was thinking long tubes and resonators, with cheaper cat back. But like I said this is her truck not sure she wants a loud truck again. No more big block straight pipes like she drove through high school now that we have a kid. What are my other options to gain performance and maybe some mpgs. I will be researching some high flow cats. Has any one used them and if so what are your thoughts. Thanks in advance Aaron


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[Duramax05blk]

Well with minimal effort i was able to discover a well known fact all high flow cats are basically a GIMMICK. They all flow decent. I did however end up welding some magnaflows in replace of the factory units. Just gotta weld up some nuts on the broken manifold bolts and get them out and install the new plugs and wires and, few other pm items. I already purchased new factory exhaust manifold bolts but im thinking of going with a stud kit. Does the stud kit seem to be an upgrade from the factory grade 5 bolts? lastly i have found the torque specs for the exhaust manifolds, just not the sequence. Does any one know the proper sequence? I know to start from middle work out evenly from side to side as a general rule of thumb. I would like to follow what ever GM specifies if any one has it would be appreciated thanks