Well, what I did was purchased a USB to ALDL cable ($80), Tunercat Winflash ($20), and Tunerpro (Free from tunerpro.net), as well as some free BIN files and tables. I downloaded my original BIN file from my PCM and edited the file with "tunerpro", then uploaded the changes with "winflash". What year is your PCM? I am assuming it is '96 or newer, so you would need a different cable and software, but either way you can modify parameters to account for tire size, gear ratios, etc. I'll have to let you know how my calibrations turn out once the car is derivable.