[Mr427]

Hi:

It sounds like either of two problems: 1. Electrical and 2. Vacuum leak.

The electrical problem sounds like you are getting electric power to the coil only while the ignition switch is turned to "start". That means you have a wiring problem where you are not getting any power to the ignition coil during regular "on" on the ign. switch. So you need to check all the connections and routing to and from the MSD box.

The second problem sounds almost like there is a plug missing from one of the port openings on the intake manifold, leaving you with a mixture that will not fire. Check all plugs and hoses on the manifild and on the back of the carburetor base. You may not have sufficient vacuum to fire the engine.