You obviously haven't paid any attention when drag racing, or you have a rigged track that gives people false hope! An 89mph trap with a 2.55 60' time would be around a 16.0-16.2! For you to run a 15.0 with the 60' time you had, you'd need to trap closer to ~96mph.
As for launching, good luck with your differential. With 3500rpm launches and reving to 5000rpms, you're sure to be either clutchless of diffless.
For an optimum launch, I rev to about 2800rpms. At the line I'll let the clutch pedal out until it's almost about to grab. Once ready(when I get the green), I start to slip the clutch and rev the motor to keep the rpms at about 2800-3100rpms. Once you've got a little momentum and you've completely let out on the clutch pedal, you'll be right at the point of your secondaries opening and your powerband begins. After that you're on your own.
Mark
