I'll see if we can dig up the old dyno plots, but the difference was in consistency, not absolute numbers. For example, if a stock car was about 160WHP/210WTQ, with a 3" CBE, it might do one run around 162WHP, then 150WHP, then 155WHP, etc, something different every time. With the 2.5" exhaust, we would see the same numbers on every pull (at least until the FMIC would heatsoak, ha!).
Ian