Saw this exhaust chart from Magnaflow in a magazine, just thought I'd post for the hell of it.
2-2.25-in 150-200CID 100-150 HP
2.25-to 2.5-in 200-250CID 100-200HP
2.5-3-in 250-300CID 150-250HP
2.5-3-in 300-350CID 200-350HP
3-to 4-in 350-400CID 250-550HP
