Unless you have custom built headers, tuned to your power curve you don't have to worry about too much scavenging - it just isn't going to happen without a tuned exhaust.
I haven't found a muffler I like, so for now my car is 2.5" pipe from my long tube headers and turn down at the axel....
I run 3 inch exaust fabbed my me, they come from the 3 inch header flange to 3 inch exaust pipe run to the rear end with 3 inch 2 chambered flowmasters. as for flowmasters haveing alot of baffels this is bull, they have 3 v shaped baffles in the 3 chambers, and 2 v shaped baffels in the 2 chambers. I have cut the case open on them and copied them before. only using a square case. In my opinion flowmaster is the best you can buy, I prefer them over all competitors. But also to each their own. As for exaust....the faster the exaust escapes the better your car will run. AS LONG as you have full length headers. Why do you think on the strip ET's are better with open headers?
I run 1 5/8 headers with a 3'' collector 2 1/2 exhaust 2 chamber 40 series flows (my favorite muffler also) 91 5.0 with about 100,000 miles b303 cam and 650 holley 12.82@103 spinnin like a sob! Here's the vid
This is what i normally do as well. hooker headers, 3 inch collector, 2 1/2 inch pipe and flowmaster 40's. Cant wait to to get the drivers side done and the passenger side collector welded on and hear how it sounds with the v8.:bananaman Very nice video btw!
