Hi everyone, this is my first post and I'm hoping someone can help. I'm actually in Australia and have acquired a 1969 Mustang which is running a 351 Windsor. It has an Edelbrock Performer 351 W Manifold matched to a 600 Holley Carb. My problem is there is a fuel leak out the side of the carbie near the gasket to manifold. I have tried new gaskets and still she bleeds fuel and then affects performance so she eventually wont start. When I first put the new gasket on she kick over fine and runs nice. However when I turn it off and then try and start it again, the problem starts and fuel leaks.
My questions.
(1) Is this set up maybe meant to have an adaptor plate??
(2) I've used gasket glue to try and help the seal more, is this necessary or is it bad??

It worries me that the manifold inlets are like two ovals, yet the 600 has the four circles. That's why I ask if an adaptor plate should be used.

If anyone can help or has this set up on their stang I'd appreciate any help.

Kind Thanks,
Craig.

 

The manifold set up (ovals) to carb (circles) is normal and should work fine.
No gasket glue is necessary or desirable. It sounds like the seal may be warped. Pull the carb off and lay a straight edge across both the carb base and manifold pad and verify they are dead flat.

 

Also check if you have enough surface area on the manifold side walls. I have seen manifolds where the side walls were too thin, screwed up in the manufacturing process and they would never seal.

 

if the carb is not mating to the manifold perfectly you have problems with vacuum leaks (car will run rough or not at all), but this should not cause the carb to leak petrol

it would be great to know where exactly you leak the petrol (picture?). is it between throttlebody and upper part, is it at the fuel bowl ?

and yes. no glue needed or wanted anywhere near the carbs gaskets

 

it sounds like you have a needle/seat stuck and flooding.

 

Yup, sounds like either the needle valve is sticking, has dirt in it or is adjusted to high. After you run the car, can you see fuel dripping inside the carb?

 

First thing's first. What's the fuel pressure? Should be no more than 6.5psi at idle. Second, what's the float level at? They need to be set right. Checking those 2 things will eliminate the possibility of a bad/jammed needle and seat. Also check the bowl mating surface and metering block mating surface for straightness, and use the blue non stick gaskets(the Quick Fuel ones can be had at Summit/Jegs, they're about 1/3 the cost of the Holleys and probably better quality, I have no problems with them).