Good response by all. I'd like to comment on jetting. A stock carb is jetted for air fuel mixture. Probably about 13-14 to 1. You could put the 1 barrel on a 454 and the air fule mixture would still be correct; just not enough air. 1 or 3 carbs are still jetted correctly are going to be very close to stock. The difference will be throttle position. With 3 holes feeding you engine instead of 1 they will be open less for the same total air, which really runs your engine.
I've run 3 Holly 280 CFM carbs at Bonneville for over 30 years and the jets have remained near stock all that time. They were stock at #52 and occaisionally I change one to a #50 on each carb, that's for the air density.
Good luck! 3 carbs always looks good under a hood.
