wurmhole

Finishing my fully rebuilt 92 civic hatch, never done exhaust work and just bought a welder and have some questions. Cobbled together an exhaust with some aftermarket pieces that came with the car and some stock pieces. Its an aftermarket b18 header with a 2" exit where the donut gasket goes, then a 2.5" Tsudo(?) resonator and b pipe and a gsr stock muffler. Did I measure the diameter right? I measured the inside holes with a tape measurer at the flanges. Would one of the magnaflow cats with the flanges be the right side or do I need some custom ones? Thanks for the help