I posted this on another forum but I wanted to get some more opinions.

I rebuilt my holley 650cfm double pumper carburetor (List 4777-5) and after reinstalling it, the engine had a high idle and unresponsive idle adjustment and idle mixture screws. I pulled the carb to verify the transfer slots on the primaries and secondaries were not over exposed and I noticed that the base gasket was wet. I did torque the carb to I think 75 or 80 in lbs per holley's website. The transfer slots looked ok so I am hoping this might be related.

The image shows what the gasket looked like after about 15 minutes of run time. There were no external fuel leaks. What would normally cause this? Warped baseplate?

You could put a straight edge across it and you would know for sure. Looks almost like it might be pulling fuel from the power valve. There is so much fuel in the intake floor it's pulling it from somewhere. Double check the gasket under the power valve because sometimes they can get off center when you install the valve.

Gus

Thanks I believe everything was installed correctly but I will double check it.

Would a blown power valve cause a vacuum leak?

Your base gasket is smaller than the hole in the intake manifold, the air fuel mixture from the idle circuit on your carbs primary's hitting it making it wet
Trim the gasket back so it doesn't hang out into the airstream

I am not suggesting this is the problem, but, a ruptured power valve diaphram will alow intake vacuum to pull fuel directly from the bowl through a 1/8 hole so it just creates overly rich condition. Not a vacuum leak per say. Check the secondaries also, when they are open too much at closed throttle they act like that. . What number carb are we talking here those fiber gaskets often tlook like that nothing abnormal there in my opinion.

That does not explain the fuel puddling on the intake floor.