[njsteve]

I had a similar experience but it was the result of not having those little copper fabric ground straps bolted to the engine block from the firewall. Without those little straps your ground will back feed up the temp sender, oil pressure sender and starter wire harnesses and burn out your gauges, and the points in your distributor. The car will barely run over 1000 rpm.

I only discovered it when I was ready to run in the new motor and hooked up an aftermarket temp gauge with the long coiled metal sender tube. When I placed it onto the top of the cowl to start the engine, a whole bunch of sparks flew off the metal line. It looked like a 4th of July sparkler. Once I hooked the grounds back up, the sparks magically went away. And when I replaced the newly melted points, the car ran fine.