[62LS1]

I saw that you turned in your old booster. Each of the pedal rods (rod between booster and brake pedal arm - which may be partially covered by the boot) has a number/letter, etc., stamped into the rod itself. The CARDONE brake catalog will cross that pedal rod ID to a part number, usually for both loaded and unloaded boosters. Loaded has the MC attached, unloaded is the booster by itself. The booster by itself is typically the best option as they are more commonly stocked at the parts house and then you can put the MC of your choice back in place. By that I mean drum/drum, disk/drum, or disc/disc. Not much help since you turned in the original, but it might help somebody else.