That might be a little too big. Holley never figured out how to do the adjustable air valve thing. They were too busy selling vacuum secondary carbs and power valves. You should trade that Holley 3 barrel to me for a 400 cfm Holley. :rofl: I have run a 750 cfm 340 TQ on a 1967 273 2 barrel motor. Ran fine for what it was.