That is a good box. It has 1 dedicated retard circuit.
If the OP already has and MSD-6AL you can do an add on for a 2 or 3 Step Ignition Retard as well as a 2 or 3 step Rev Control. That is what I did.
I wired mine up so they 2 of the retards are active on 1 Hit. This way I can mix and match Pills to fine tune the retard. Add up both pills you use = the retard on the hit.
This is the add on to the MSD-6AL. I bought mine used for $60.00 works like new.
