No math needed if you do enough track testing. And trust me I have done a lot of track testing. When you do a budget build engine without all the bells and whistles high rpm does not pay dividends. My Sons 3200 pound combo is now running a 4.10 rear gear. My combo with a 14-32 and a 4.88 gear cannot even make a full quartermile pass without running out of usable rpm. We have a 1000 foot race later this year and I’m hoping I can make that.