Buddy of mine had an edelbrock catback on a 89 firebird with a 350 TPI. Had edlebrock headers and no cat. Y-pipe, single 3'' to 1 muffler with two tailpipes. It sounded VERY nice. It sounded so mean.
With just exhuast he was running 8.8's in the 1/8th. He was beating LS1's and GT's. Just because he got amazing traction.