Re: Dual exhaust or single ?
You can run a single exhaust and have great power, but still need a high flow cat. If money is a problem, then do a cat back for now. Just make sure on a single exhaust that you run larger diameter pipes. My 454 does fine with single 3.5 inch so a small block with a 3" would be fine. The cheap high flows are weld on units and won't bolt right in, so if doing it yourself... must be able to weld. You can get a good set of headers and use factory y pipe if keeping your stock cat. Then out back use the flowmaster 50 delta series for good flow and sound with a little less interior resonance. If you CAN do this job yourself, and can afford two cats/mufflers then dual away and use a crossover to equalize exhaust pulses. Lots of choices, but don't go too large and slow down your exhuast gasses or you will lose a lot of bottom end power.