Ok, we're talking about my '82 'maro. Ran out of room under the car for a decent sized exhaust system for the car so it's going to be a set of outsiders with fenderwell headers..... (I like my cars low, btw)

The engine is a steel crank 6" rod 383 with flat top pistons, heads will be aluminum (not bought yet). Cam will be a mechanical roller with rev kit--no cam specs yet, got to get the rest of the pieces lined up first... 750 4 barrell carb on a single plain intake. RPM will be about 7500 max.

Question is, the outsiders will be 3 1/2" tubes with a muffler inside them (or at least a reasonable facsimilie of a muffler). Wondering what size and length primary tubes to run, and whether a not I should make them a set of step headers??? Should it be 3 1/2" or 4" collectors, and how about a guess on the collector length, too???? I'm building the headers, so we're not stuck with something some manufacturer thinks should work....

Oh yeah, transmission is a 5 speed so no concerns on all that tranny and converter stuff.....I still like having 3 pedals....

Thanks for the help.