[csx700?]

actually it's "spaulding" and i believe later on it became "grant". the distributor is basically split in 1/2. instead of having 8 cam lobes for the points to operate on it uses 4 and has 2 rotors (on the same drum) and 2 distributor caps and 2 coils. from what i understand this system has advantages over a normal distributor (less point bounce, more dwell time, less chance of cross firing, etc...). i have one that i purchased from an old days shelby employee that i have not decided whether i'm going to use or not. from what i have heard someone is supposed to be reproducing the caps and rotor, the points are readily available. as per ricks post below shelby listed this as both an option and a "over the counter" performance upgrade.