I have a 74 Monte with a 350 motor and TH 350 trans. The motor is not original as the tag on the radiator support says 2 barrel and the motor is a 4 barrel. I live at a high altitude location (5100 feet) and I want to change the 4 barrel to a Holley 2 barrel, 500 cfm. My question is if the 2 barrel will be better at this altitude than the 4 barrel?

 

I really don't think there will be a major difference from 4bbl to 2bbl. Adjustments need to be made to carb you have. Some info online if you need additional help