Check your voltages before and after the VR with the different ones you have sounds like you may be missing a ground somewhere more than anything. I would check to make sure all your grounds are clean, tightened and making good connections.
1974 El Tigre 400 - New Vintage Racer
1993 Mach 1 583 bored .060, sc10 II skid.
1978 and 76 Jag 3000 FA - both sold 1980 Jag 340fc electric start (parts sled) $50.00