One point on the fuel cap leaking fumes..............the fuel cap is VENTED*. It’s suppose to leak fumes.
* As opposed to a modern cap that is unvented and the tank is vent through the charcoal canister.
Unvented cap on the old truck will create problems:
Like fuel starvation
Might even crush or deform the tank with vacuum as it starves the pump.
Have seen the tanks suck in many times due to no vented cap on old rigs.
Also see it on rigs with EVAP canisters that plug with dirt.
