Tried one out long ago when they first came out on a 75 Olds 98 455. Carb worked but the big Olds felt like it was powered by a 260. Had to keep your foot into the gas to make the big car move so gas mileage sucked compared to the Qjet. Put another Qjet back on and things went back to normal. I believe it had the reverse idle screws. IIRC, Holley literature at the time (late 70's, early 80's) said it could replace any Qjet on any car
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