Friend of mine had one of these on a 74? Dodge 1/2T shortie pu. We later swapped a 440 into that truck. The darn Holley 2bbl would "stick" the butterflies at idle, causing a jerk at the gas pedal when they released. Caused partly by engine vacuum, did not do this when not running. And, it was a "smog" carb, lean as can be up here in the cold of the N end