RPM shifting

OK I'm finally going racing, need to know what I should be shifting at. 72 Duster with full uniform, 4 speed, Center force dual friction clutch, 8 3/4 rear end with 410, large u-joint. 440 around 525HP. 255/60/15 drag radials. I was told too leave at 2500 but where should I be shifting after that, Crane fire ball with built in limiters, where should these be set at, do not want to break it right off the bat. this is just for fun.

Thanks.