Holley Flooding Engine and Spewing Gas

Thanks everyone for the quick replies. I've had the needle and seat assemblies out more than once. Sprayed them off with carb cleaner then gently blew with an air nozzle.
In the book I purchased I saw a special tool for testing the power valve, but is there a way to check it without that? It looked rather pricey.
I still have some off the old parts like the needle/seat and the old power valve. I guess I could try putting those back and to see what happens since there's nothing left to lose at this point. I'll also go back to examine those passages pishta mentioned. I'll post back later today with the results.


That’s not a power valve issue. The only way fuel can blow out of the vent is the needle and seat aren’t shutting off the fuel.

Why it’s ok on the bench and not on the car I can’t say. If the float level is correct, the floats aren’t sunk and the fuel pressure is 7ish pounds or less the only way fuel can get out of the vent is the needle and seat isn’t doing it’s job.

When you were going through the carb, did you happen to remove the floats? Just curious. And IIRC those carbs had brass floats. At least they did in the 1980’s. I haven’t been into a newer one.