Today at work I was installing a FAST fuel system in a Corvette and would very much like for it to be controlling timing. FAST as with most aftermarket EFI controllers will not directly drive a coil and so if we want the aftermarket EFI to control timing this generally means a CD box like the MSD 6a or 6al or equivalent. With this style setup the pickup coil from the distributor will be wired to the crank trigger input of the FAST controller and the points output of the fast controller will go to the points input of the CD box. This is the absolute largest possible footprint for a coil driver. lol. I believe I have found a way to use the coil driver in the GM HEI distributor. The 4 pin ignition module. Which is a small coil driver. Here is my idea on paper..