Driving it pops cuts out?

Re check your connections. Make sure you did not disturb any other connections at the distributor or coil.

Roy

Also, disconnect the small plug, drive it, and see if the problem is still there. If not, it may be developing voltage spikes or it could have a bad internal diode. You'd find that with a professional load test. With a bad diode all you'll be able to get is exactly one third of its rated output and "ripple" will be very high.

Also check all the ground wires. Have seen ones that look fine but had corrosion under them making a ground most of the time but them not grounding.