Disc and all-drum cars have MC's that are mechanically different. If I'm correct in thinking that the 1967 was the first front-disc Imperial, you are headed for trouble putting a later MC onto your all-drum 1966 car. Try a 67-69 Full-Size (Newport?) Chrysler MC. Those cars still had 4 drums. Disc MC's are valved differently than drum ones for the "front" circuit. The item above fit onto my 1960 with only the plunger rod that attaches to the brake pedal needing to be swapped, retaining the original one. The 1960 has the booster mounted over the MC on the firewall, not inline. -Kenyon --- LOYALZ@xxxxxxxxxxx wrote: > Does anyone know if a duel chamber master > cylinder from a '71 Imperial will fit on a '66? I need > to switch my single chamber master cylinder with a > duel chamber, but I'm not sure which one is > compatible. I saw on the '66 repair page where > someone has switched, but they didn't say what > the > duel chamber MC came from. > > thanks for the help, > > Loyal Stern > 66 Crown Coupe > > > >