350 small block, horrible gas milage

[71C10Guy]

I have a 71 C10 pick up, which has an almost stock motor, just a cam with slightly longer duration and an edlebrock 650 carb, possibly rebuilt, but I'm pretty sure it's new ( my dad bought it at AutoZone).
Anyways the truck constantly reeks of gasoline, but only when not running (not a hole in the gas tank), and has trouble going over 70 miles per hour. I took my friend on a 30 minute drive yesterday on a full tank of gas and had to stop at a gas station on our way back because I had an 8th of the tank left. Basically, unless my fuel gauge was inaccurate, I got around 2 miles per gallon. The hoses and external fuel pump (gen 2 block) are dry, so I don't think the gas is coming out of them. The truck isn't missing as far as I can tell but has a rough idle, ehich can be fixed by adjusting the idle screws.

Has anyone experienced this or know of anything that could be causing this? I'm tired of driving from college to home and spending enough to fly my entire family on the same trip.
Thank you,
Mark

[weq92f]

A leak.

Open the hood and check all around the intake and carb for signs of fuel leaking while the engine is running. Check everywhere. You'll just about have to find a running stream of fuel leaking somewhere.

Check under the truck for fuel leaking to the ground and check the tail pipe for fuel leaking out of it. Run your hands all around the exposed portion of the tank. Follow the fuel lines as well.

You'll find a leak somewhere.

Hth,

-klb

[71C10Guy]

Originally Posted by weq92f

A leak.

Open the hood and check all around the intake and carb for signs of fuel leaking while the engine is running. Check everywhere. You'll just about have to find a running stream of fuel leaking somewhere.

Check under the truck for fuel leaking to the ground and check the tail pipe for fuel leaking out of it. Run your hands all around the exposed portion of the tank. Follow the fuel lines as well.

You'll find a leak somewhere.

Hth,

-klb

Thank you for replying. I have checked the lines around the fuel pump and up to the carb. I still need to check the lines from the tank and look into the exhaust pipes, which have backfired frequently in the past month. I'll post back if I find anything
Thanks again,
Mark

[71C10Guy]

Oh and weq92f,
I don't know what kind of truck you have or the engine, but based on what I described, a 350 small block with mild cam and preformance intake, as well as a 700r4 transmission (I don't know my final drive) what speeds should I be able to reach? Topping out at 70 seems very low to me, seeing as most of my dad's old cars and trucks with slightly more powerful engines can break 130+.

[robs71]

check your oil for being overfull or smelling like gas in case your carb is bleeding down internally..2 cents

[truckster]

Originally Posted by robs71

check your oil for being overfull or smelling like gas in case your carb is bleeding down internally..2 cents

Do this right away. Gasoline is a really poor lubricant...

[71C10Guy]

Originally Posted by robs71

check your oil for being overfull or smelling like gas in case your carb is bleeding down internally..2 cents

Ah, yes. Good times from my first motorcycle. I certainly will. If that much gas is draining into my oil I'm surprised it hasn't blown already. But regardless I will check.
Thank you for the suggestion,
Mark