I've been working with this spreadsheet for a while. If you want to download it, you can unprotect it and change any value you like. If you find an error in any of my formulas, please let me know and I will update them. It is stored on my public One Drive and is an Excel spreadsheet. It has the following tabs: 1) Tire Size Calculator - also allows you to compare different tire sizes 2) Speed - Tire Height - RPM Permutations - includes options for various final drive ratios 3) Engine Info - Calculates engine size and figures static compression ratio 4) Transmission Selection - Compares many popular transmissions and first gear ratios 5) Quarter Mile - The least precise of them, it might give you a rough idea of HP and ET https://1drv.ms/x/s!ArrA9ZJ8SJPR3T2UXoLew1Vndzqb?e=iI7JAd