Norm at Precision Automotive dyno'd the engine today.
It kept stumbling when it got over 5500 rpm. Norm tried the fuel pump lines, the fuel pump, the points, and then jets, power valves....etc....and nothing fixed the problem. Almost an hour laster, and Norm found that the problem was the coil.
It was a restored coil, and I went to check the box. Based on where it was made, it just figures:
Pic of Norm trying to find the problem:
