Leaking Fuel Tank

You may want to try a professional repair service. Check http://www.gastankrenu.com/welcome.htm
Is your engine sitting level? Are your motor mounts OK? I ended up shiming the right motor mount to get my header off of the gas tank shield.
Jin

Depends on whats wrong with your tank. Many leaks turn out to be the connecting hose up top to the outside gas filler, and is fixable by replacing the cracked filler hose with a piece of FUEL-PROOF hose, not radiator hose. The tank need not be removed to do this. If the tank is perforated, youll need to get it out of there to do the job properly, I'm afraid. The #6 pipe gets closest to the fuel tank heat-shield but shouldn't touch unless you're running aluminum SVO heads with severely raised exhaust ports, or maybe a Windsor block. Empty the tank, loosen the hold-down clamp on the bottom, and simply move the tank outboard until it hits the upper body. Retighten the clamp bolt & if necessary, put a second screw & nut through the adjustment slot to keep the adjustment from shifting. The tank will normally move about 3/4" sideways but full of gas, its too heavy to shift without damaging the thin tank metal.