Check the output on the VR then Chuck it ought to be giving out around 14.5-15 volts.
If you got a big Chilton manual there's a really easy test for it.
Make sure that the reg is properly ground against the firewall, not the motor.
If there's a bad connection at the bulkhead connector block that'll do it, try running a jumper wire from the positive batt post to the headlamp direct and see what happens