NEW Holley 80508 (Model 4160) The carb was torn down to check for trash and/or power valve issue back during the last debacle with the motor that has been well documented.

Now, getting gas pooling on top of manifold on Driver's side (approximately midway, and appears to be coming from about midway of carb). It is leaking/accumulating AFTER car has been cut off. NOT DURING RUNNING (the best I can tell anyway, but it is definitely accumulating with motor OFF).

I see no VISIBLE leaks including around the fuel bowls, but there is a gasket bewteen the lowest plate on the carb (that mounts to manifold) and the body of the carb (is This the Throttle body gasket?) that APPEARS TO BE WET to me the best I can tell. There are approx. 6 screws that screw from bottom up into carb. I have (re-)tightened these already.

Before I order another and have to pay shipping, would this gasket possibly leak, with motor off? And is it the throttle body gasket?

If NO, where else would the *&^% carb be leaking from on that side?

Any thoughts?

As always, thanks for your help and thanks for Chevelles.com!!

(The base gasket was replaced, but unless I'm badly mistaken, I can't see how the base plate gasket could drip gas to this degree with the motor off.)

I have seen the leaking gas you described and it is usually due to a high fuel level in the float bowls. When the engine is shut off the fuel level in the carb can rise to the point that is pushed out of the boosters, drips on the throttle blades and seeps out the throttle shaft. The high fuel level can be due to a high float setting, high fuel pressure, a bad float that has become full of fuel and is sinking causing the bowl to over-fill, or some dirt under the inlet needle which will also cause over-filling. I have also had a Carter carb that had a tendency to boil the fuel in the carb when the engine was hot and caused all sorts of problems. The gas you see on the gasket is just because of its proximity to the throttle plates.

Editing my initial response post. First said it was not leaking after last test drive. Just checked it, and indeed still getting a bit of a pooling.

Had a "mystery" problem surface with my Holley (3310) this past summer. The car didn't have the "snort" it used to, and all of a sudden the car would be very hard to start after sitting for a few hours. It'd crank,crank, then fire. After a long cruise one day I parked it, and left it with the hood up. Someone noticed a puddle of fuel under the front bowl of the carb.

It turned out the accelerator pump diaphragm had a teeny tear in it. Over time the fuel would leak out and boil off on the manifold, leaving the bowl empty (hard to start with no fuel or accelerator pump). Also every pump of the pedal would squirt fuel out instead of in the engine (no "snort").

The culprit was that a long time ago I had a 50cc pump housing/lever/and cam on the carb. I had to remove the housing/lever (due to manifold clearance on this buildup), but forgot to change the long throw pump cam. It ultimately stretched the diaphragm to the point of tearing.