supercharged24,
I hope this doesn't segway too much but I've had a little experience with a similar problem. A car that I had experienced a flat mid-range and some heating problems (glowing headers) with a car that I "opened" up. I went from the headers to a 2.5" pipe, then to 3" mufflers that dumped short of the rear end. While this was a SBC 383, I think the semantics are the same with respect to scavenging. I know it sounds crazy, but without enough back pressure the resulting shockwave might not effectively scavenge "all" of the hot gasses from the exhaust port quickly enough.
I know that you definitely want to scavenge as much of the spent gasses when you have a huffer, so I'd suggest that you talk to a pro that can find a happy medium between effective scavenging and back pressure.
I ended up going from 2.5" pipes to 2.5" mufflers, then out to 2.0" tailpipes for a blown SBC 383 66' Nova. Worked great and I got the mid-range back after that. I've thought about doing that to our 95 SC, but have yet to find the golden techno-nugget of information.
Please let us know what you find out...
M Randolph