fuel leak

[jonnymel]

Help Please
I am trying to get my Truck running for this coming weekend .....for the bride and groom to leave the church in .
I have a 1960 GMC 454 with a holley 750 carb. I have done away with the crappy fuel cell that was in it to make room for the exhuast and fabricated a bracket for an older style corvette tank mounted in the bed behind the cab . The tank will be mounted on this bracket and inside an antique chest. the tank is mounted about 5 inches above the bed floor.
After a quick drive and return home to make some adjustments ( new motor and tranny). the next morning I noticed fuel had puddled on the top of the intake...i pulled the carb off and there was more fuel inside the intake.....i pulled the plugs and fuel poured out of one of the cylinders . I drained the oil and am ready to start again.

have i made a mistake in mounting the tank where i did ? i can install a fuel shut off at the tank but shouldnt the carb stop the gravity feed of fuel from entering the engine ?
Any help would be greatly appreciated ....i have little to no experience working on carbs......( this was a freshly rebuilt carb )

[1963c-10]

I'm inclined to think the float is sticking or there is dirt in the needle valve. Is it an electric fuel pump or mechanical?

[jonnymel]

Hi
It's a mechanical fuel pump
I will replace the needles and seats and check the floats. I will try to check it after repairs before I re install

[Chevy Fleetside]

Dose the fuel pump have three lines or two. I have a BB and my pump has three lines. One is for fuel to come in, one for fuel to the carb and the last (1/4" line) is for pressure relief. I notice alot of fuel would come out of that relief while the engine was running and after it was shut off. Had to run a line back to the tank. I will try and get some photos for you later.
Found this picutre on ORielys site. You can see the 1/4" return. Before I hooked this up my truck would flood after drivng it.

[jonnymel]

That is interesting ....it only has 2 lines ....
I have replaced my needles and seats and new brass floats ,installed a fuel shut off at the tank....
I will try it if this doesn't alleviate the trouble maybe I'll have to replace the pump.
Wouldn't the pressure exhaust back through the tank vent ?
I'll let you know how it pans out
Thanks
Jon

[1963c-10]

Ive seen fuel pump diaphragms go bad and fill a block with fuel, but with the fuel coming in from the intake as you described.....I'd start with the carb.

[Captainfab]

Is this Corvette fuel tank properly vented?