The stock crossover is TOO far from the exhaust valves to accomplish what a properly designed crossover accomplishes, IMHO. I ran my '03 Bonnie with an exhaust system with NO crossover for a few thousand miles, and the torque and horsepower were both higher than with the stock headers with crossovers. The main thing is to get the jetting for the carbs proper (or the tune for EFI) when one makes changes. A good tuner with a dyno can separate the BS from reality rather easily.
2003 T-100 (790cc), NARK, NH Togas, 8100 rpm rev limiter, 158 main jets, 42 pilot jets (less than 1 turn out on pilot screws), stock needles--no shims. 13 A/F ratio from 1100 rpm to 4000 rpm; 12 A/F ratio from 4000 rpm to 6000 rpm; 13 A/F from 6000 rpm to 8100 rpm.:D
2007 Tiger 1050--White:D--SW-Motech crashbars, Skidmarx rear hugger/chain guard, Calsci +7 windscreen.