What do I need to do my electrical system in my dart.

Buy yourself a really nice test light. Not one from Harbor Freight.

You'll also want to run the same size ground wire on the battery as you do on the positive side cable. Do not ever expect the body or frame to be a good ground. Because it's not.

Also you need to use a ground cable of the same size on the back of each cylinder head. Don't shortcut what I am saying and you'll have a race car that works correctly.

Wiring is not difficult, but it requires taking your time and making quality connections.

Tom