First slant, multiple questions

I had a 1969 Dart 225 w/ Holley 1920 for 18 years. It acted the same, wanted to stall off idle and such. Went thru head rebuilds, multiple carbs, finally even a whole different rebuilt long block. When it still idled rough, I tried a 4th carb and that was the charm - idled like a kitten (car stolen 2 months later & never found). As many have found, most Holley 1920's you get from auto parts are bad. There is a sealed metering block which most rebuilders don't touch. Some guys here know how to blow thru the bottom holes to clear out the metering block. I now have a 1964 Valiant 225 with a Carter BBS carb. It runs so smooth you can almost not tell the engine is running. The small silenced air cleaner helps. That carb is similar to the Carter BBD used on gazillions of small-block engines and is easy to rebuild and understand. Not sure how economical it is. For that, I think there was a Holley Economizer carb sold after-market in the 1980's that fits a slant, though people say they are impossible to rebuild.