Well, they both atomize fuel and introduce the mixture to a common manifold. That's about the only similarity between the two. The Holley platform carbs are relatively cheap, super easy to tune, easy to work on, and plain simple. The Q-jets require metering rod changes along with jets and you have to dissasemble the whole damn thing to do it. With a holley you just drop a bowl for a jetting change. Look at the price of a brand new Edelbrock Q-jet, and a brand new DP. The Q-jet costs more. Now, the AFB platform witch is the "other" carb. is a good one, but it also has the assorted metering rods and stuff. A properly tuned Q-jet is a great carb that will provide years and years of reliable service. But, getting just right may(will) take a bit longer. IMO. I run an 800 CFM Edelbrock (AFB), manufactured by Weber. I was lucky, that was good out of the box. Now as for fuel economy, if the boat has a pump poking out the back, it'll probly get shitty fuel economy regardless of the carb(s). But who cares. If we can't afford gas, we need to sell our boats.
fog