[brap999]

scotts62 - I think you confirmed what I was afraid of. The bore size on the master cylinder is larger diameter than the stock m/c as well as the hole in the firewall, so it's leading me to believe that the part of the brake booster that connects through the firewall will also be larger than the hole in the firewall.

I may just see if a '70 something master cylinder fits this brake booster I already have, what ever it may have come out of.