My dad had an '80 Buick Regal with a Varajet or a Dualjet on it . . . it had a band-saw engineered V6 (take a small V8 and lop off two cylinders
). It was poorly balanced and anemic to drive - but probably not the carb's fault. With so much focus on emissions and cost control the driving experience was low on the list of priorities . . .
You'll be looking for the early design '79 or '80. After that they were fitted with electronics to feedback to an engine management computer. There are some out on ebay now . . . but I think they are the later design.
Rochester Carburetors: Tune, Rebuild or Modify Any particular reason you are interested in running one of these?