For 1990-2009 cars

Application | GM SPO Group Number
--- | ---
Catalytic Converter and Exhaust Muffler Heat Shield (Front) | 3.690
Exhaust Crossover Pipe (w/Heat Shield) | 3.609
Exhaust Muffler (w/Tailpipe) | 3.701
Exhaust Muffler Front Hanger (O-Type) | 3.704
Exhaust Muffler Heat Shield (RR) | 3.705
Exhaust Pipe Hanger | 3.616
Exhaust Resonator (w/Exhaust Pipe) | 3.702
Three-Way Catalytic Converter (w/Exhaust Pipe) | 3.685