Searching for the right 1BBL for a 66 dart 270

My 64 has a Carter BBS. My 69 Dart had a Holley 1920. Don't know what year they switched. I think the BBS is more reliable since 1920's have a sealed metering block that most rebuilders don't touch and are often clogged. A lot of bad 1920's out there. I went thru 4 over 18 yrs until the last one made the engine run great. Later years had the Holley 1945, which some people swear by.

If you want best mileage, there was a Holley Economaster in late 70's. However, a slant really needs MPFI to get optimal distribution, but that is currently roll-your-own.

Not much interest or value in keeping a slant original, if that is your goal. Most people prefer upgrades.