[fastd]

tbk289,
I am looking for the same things you are.

I currently have the stock ERA undercar with 2" Dynomax mufflers that go all the way out the back to the chrome tips.

I am changing the carb from a 750 cfm 4160 with vacuum secondaries to a 600 cfm double pumper 4150 HP. It was recommended that I change out the exhaust also; I always wanted them to exit in front of the rear times, so now is a good time.

I will still use a muffler. I have come to find that there is a lot of science involved in the exhaust.

I think I am going with a 2.5" pipe. As for the muffler, a Flo-Pro was recommended. I have noticed a pretty broad cfm range that mufflers produce, however, it is not easy (so far) for me to find what cfm and decibel ratings most mufflers carry. I am working on trying to figure out what the optimal cfm requirements for my set up would be and then try to piece it together. I think the bottom line is that bigger is not better; you trade off bottom end torque to top end hp...best one can do is try to find a happy medium - requires a determination of how you really want to drive your car, street, track.