For a while back in college, I had a super cheapo side-exit exhaust on my 74 Swinger... collectors from the Hooker fenderwell headers, to an H-pipe, in to tiny mufflers, then a 45* out to the side in front of the rear wheel openings. It was kind of loud, but I blame crappy mufflers for most of that. I don't remember any sort of exhaust smell problem, but maybe those brain cells got killed off. Could have been the beer, too...

I'd say you wouldn't have any problems with factory-type parts, or with any of those cool squished ovals from Dr.Gas...

Clair