First time down the track

Exhaust? First time on the drag strip back in 86. 71 RR with a low comp 440 with 292 Comp and headers. 3.23 gears. 14.90s at 93 mph. The next time I went to the track I uncorked the exhaust and went 14.10s at 102 mph. The exhaust was two inch pipe shoved into 3 to 2.5 collector reducers and long glasspacks. So , I figure that weenie exhaust was costing me about 90hp.