BroncoW

I have a 82 Bronco full size, I put a 4 barrel holly and manifold on it, I cant keep it from dumping fuel dow the intake, it dumped enough to dilute the oil, I've checked the floats their set properly, power valve is okay, Any help would be greatly appreciated.

Racer

Idle the engine and see if fuel runs out of the booster. (the circular thing in the centre of the barrels) If it does, its the needle and seat leaking, or the powervalve. I recently had a brand new powervalve intermittently sticking, so i'd replace it as a precaution.

82 Boss

I'm not an expert on Holleys, but here are some things I'd check.

Most likely problems are 1) incorrect fuel level setting, 2) float valve/seat not seating, 3) float sticking or not floating, 4) power valve set wrong, 5) metering orifices too large, 6) carburetor assembled incorrectly.

How does the engine run at idle and under load?
Does the carb have a vacuum secondary?
Look down the carb as the engine is idling and as the throttle is opened. Does excess fuel appear to be streaming into the intake?
Are you running a fuel filter between the pump and carburetor?
Check your needle valve seats for contaminants.
Is the power valve set incorrectly and pumping excessive fuel?
Is the choke set correctly?
Is the air cleaner element clean?

302xm

Could also be to much fuel pressure forcing the float valve open and flooding the engine. between 4-7psi is good.