This is posted as a sticky in the vehicle dynamics section, but since this forum gets higher traffic I think this is the best placed for peer reviewing this tool. Attached is an Excel 2003 sheet that determines based on an user inputed torque curve, tranmission ratios, and rear end ratio what your optimal shift RPMs are. I will be converting the sheet into a C# program over the next couple weeks for those who do not have Excel. If anyone has any issues with the sheet simply let me know as this is not the final version. Take note that in practice your actual shift point should be slightly higher than those outputed by this sheet due to the deceleration of the vehicle during the shift. I have a tractive effort sheet which factors this in but due to the labor in the sheet between me and my friends I am hesitant to post it. Just know that its between 100-200 rpms depending on vehicle speed and drivetrain inertia.