Anyone using a programmable MSD box?

It would work perfect for you since you can program multiple timing curves and change them based upon the fuel you have available. Got race gas? Pop in the aggressive curve. Got pump gas? Pop in a mellow curve. No need to ever touch the dizzy once its set up, its all done with the laptop.

In simplest terms, it retards timing. You lock out all mechanical advance in the dizzy and set it to the max advance you want. Then you program it to pull out timing at whatever points you want. For example- you want initial advance of 20* and a max advance of 38*. Lock out dizzy and physically time the motor to 38*. Then you program it to pullout 18* from 0 rpm - whenever you want the curve to start, giving you 20* advance. You can then program when and how fast the curve goes to full advance by pulling less timing out to bring it to the full 38* that the dizzy is set at. You can even simulate vacuum advance with a common GM map sensor.

The system can still give 20* start retard just like any MSD box to make starting easier. It also has several retard options. You might like those... ;)

I am currently running it just as the ignition because of time restraints getting the car ready for Mopars in the Park, but will lock out the distributor advance and use it to the fullest this weekend.