[Coloradocobra]

You may want to add a short heavy ground from the frame to the engine or bell housing if you do not have one already. Your ground path to the engine could be running from a sidepipe hanger or something similar if you do not have a heavy ground wire to the engine since your motor and transmission mounts are effectively insulators. Smaller engine to frame grounds are fine for electricals but inadequate for starters.

Just a thought,

Gary