No spark

Oops I did forget the engine size. It is a 4.2 in line 6 with a Weber Carburetor. It does not have a port too plug in a code reader. They did not have them until later years. And the mechanic is willing too stop by to plug in his portable computer to the ports next too the battery. But his scedual is not letting him come yet and since it won't start and I don't have the money for a tow. I have bin stuck waiting for over 6 months to find the problem. So any HELP would be greatful. Carrson mccleary.