Ok I've got a Performabuilt Stage 2 4L60E tranny and I have 3.73 gears. How do you go about figuring out how much the rpms are going to drop between gears. Like if I shift 1st to 2nd at 6500 how much do the rpms drop to when 2nd gear engages? 2nd to 3rd?

 

Actually that would be a little hard to determine with a stall. You can use the ratios of the trans and percentage of difference if there was no stall slip or if the converter was locked.