How to??

My distributor is just a standard 67 single point 2V setup that has had the Pertronix ignition module installed and the ballast resistor removed so it gets the full 12V. I have done no other mods to the distributor but if I understand the tuning I need to do to my build I need to limit the mechanical advance so initial and mechanical total come in around 36 deg +_ at about 2000 to 2500 RPM. I am not interested in changing distributors, just modifying the one I have to that end. Thanks for the help all. I have been testing the motor for a couple days and I can tell it is going to be a sweet runner for a little 273 4V hi-po setup. Details are on my build thread------:-)