Holley 1920 accelerator pump issues

I second that. Holley 1920 carbs have all the typical Holley problems with the metering block, the diaphragm-type accelerator pump that has a convenient leak hole to dump fuel on the manifold when it ruptures, a bowl gasket under fuel, a side-hung nitrophyl float...it's just a problem looking for a place to happen.

Carter BBS 1-barrels were available all the way through 1971 or so, but usually on a 170 or 198 Slant. There were some on 225 engines around the year of your car so if someone decides to go that route, they should be able to find a good core carburetor pretty easily. They are similar to a 2bbl BBD, so far less leaks and stuck floats, plus a leather accelerator pump cup.