TODAY I WAS REPLACING MY POWER STEERING PUMP AND HOSES ON MY 77 CORVETTE ,I JACKED THE FRONT END HIGH ENOUGH TO PULL THE DRIVER SIDE TIRE OFF AND PLACE TWO JACK STAND NEAR THE DOORS ,SO I HAD ENOUGH ROOM TO WORK .WHILE I WAS WORKING ON IT ,I SMELT AND SEEN GAS LEAKING FROM THE REAR FRAME BEHIND THE PASSENGER SIDE TIRE.BOY WAS THIS SCARY THE CAR WAS IN GARAGE .RIGHT AWAY I GOT THE JACKS FROM OUT UNDER THE  CAR AND PUSH THE CAR OUT OF THE GARAGE.I JACK THE REAR UP REMOVED THE SPARE TIRE HOUSING THINKING THE TANK HAD I HOLE IN IT ,FOUND NO LEAKS!!!RAN MY HAND BEHIND THE REAR NEXT TO THE FUEL LINES GOING IN TANK THEY WERE DRY AND THE LEAK STOPPED? I KNOW THE TANK WAS FULL AND I CHECKED AROUND THE GAS CAP AND THROAT GOING DOWN IN THE TANK IT WAS DRY.I DROVE IT AROUNG THE BLOCK NO MORE LEAK .CAN ANY BODY PUT SOME LIGHT ON THIS CRAZY THING .THANKS GLENN

duke532006-09-16 15:54:44

If it leaked once it will leak again,i believe the fuel lines are both feed and return lines,

Check the fuel lines closely...you may have an age deteriorated line. The incline may have allowed fuel to run out but not when level. Whatever the cause it should be checked and fixed right away...especially since the car is garaged. You don't want gas fumes collecting indoors.

Sounds like you may have a fuel return line leak. Not sure how it runs on a '77, but the earlier cars had the return line going into the very top of the tank on the pass. side, about mid-way, front to rear.
If the tank was full, and you jacked the driver side up and it leaked, the return line would make the most sense to me.
Even if your tank has the sending unit on the top of the tank, the return line may still go on the side. I may need to look and see on that.
You could still have a hole in the tank, but a hole at the top of a fuel tank is pretty rare, unless it's a soldered fitting that has cracked. There was a re-call in '74 for this very reason. The fuel return line fitting was not soldered properly from the manufacterer, and Chevy had to remove the tanks and repair the fittings. As a side note, this effectively eliminated any chance of ever finding a build sheet on a '74, unless it didn't get the re-call repairs.
                                  
The pic doesn't show the return line fittings on the sides of the tank, so they must be combined on the sending unit. There can still be a rubber line leaking there. Adams' Apple2006-09-16 19:09:36