I agree that the crossover should probably be left in place if there is enough restriction that the exhaust gases need somewhere to go. In my cases they don't, thus no change (small for the better but as I stated not attributing that to the mod), on a more restricted exhaust it may well change the power but I'm not so sure of that one.

I learned all I need to know about life by killing smart people and eating their brains.
Eat right ,Exercise ,Stay fit, Die Anyway!