We used to run a hose from the one vent tube to the other, with a cut out under the middle. If the float would stick open, the fuel would pour into the middle of the carb. You will have to make sure the flame arrestor fits too, dont run it without one. The other thing I would do is make sure you replace the accelerator pumps, as they are under the float bowls, and if they leak, they will leak on the outside of the carb. Im not real sure about the spread bore holleys though. As far as running lean, the auto carbs are set up that way because of the pollution, so you may need to fatten it up some. Holleys are very basic carbs, and very easy to work on. I have heard other people likeing the edelbrock carbs for marine use too. Im sure there will be other opinons, and I may have missed something too. Goodluck.
