I plugged the unused fittings on my tank by finding an appropriate size bolt and sliding into the rubber line and putting a hose clamp to hold the bolt in place.

As far as electrical wires I use crimp fittings and electrical heat shrink tubing.

In the Stovebolt Gallery ~~ "The Orange Crate" 1965 C10 SWB Step Side Build Thread

Inspired to be different. Different in a way of my own, not in a way that others strive.