Joined: Nov 2016
Coltman, you have a couple of problems running against you here. I did the same thing with my original 289, thinking that it would be better than my 'junky' factory type carb (an Autolite 4100). The first issue you'll deal with is that your engine typically uses more like 300-400 CFM with the stock cam, etc. That means with a 600 CFM carb, you are not pulling enough air through to atomize the fuel very well. The big droplet size will make your engine act lean, but still put a lot of unburnt gas out the tailpipe. This is aggravated by the fact that a Holley doesn't have annular boosters.
In my experience, you can make a Holley 4160 work okay, but never as good as a 4100 or a Summit M-series, because of the much better atomization you get. Their annular boosters start drawing fuel from a lower vacuum signal, and they also make sure it's a fine mist (mostly vapor when you get to high-flow situations). That means better throttle response and economy.
To be perfectly fair, at wide open throttle, the Holley will deliver about the same power. It's only every other situation where it's inferior.
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