Re: Excessive pressure in fuel tank.
normal for a non-return set up. One way to reduce the pressure is to keep the tank full of gasoline.
gasoline as a fluid actually decreases in volume with increased temperature. however, gasoline vapors expand with temperature. more fluid in the tank means less pressure, while less fluid in the tank equals more pressure, with increased temperature. since the tank is valved by the cap (one way valve in only) the tank will not be allowed to build negative pressure and collapes.
69 X-44 base coupe, ZZ4, 16lb nodular flywheel, Center force DF clutch + PP, Holley 600DP, Hooker super comp 1 3/4 ceramics, 2.5" dual exhaust w/ X-pipe, flowmaster 40 series mufflers.