'83 nautique stumbles/dies at warm idle

I have read many threads about the earlier Nautiques that idle poorly and/or stall when warm/hot, I thought I'd share this weekends experience...maybe it will help others.

The boat: '83 Nautique w/ 351 Commander, 640 hours, 1 owner.
My buddy (owner) has long complained of this problem. We replaced the intake manifold gasket several years ago and it improved, but didn't cure problem. Replaced the carburetor with the correct-spec Holley 3 years ago. Last full tune-up also got new plug wires. But it still continued to have this issue.

So I did a full tune-up last Friday. Plugs, points, condenser, cap, rotor. Most of the parts that came out looked good..

But what had never been changed before was the coil. It was still painted Commander blue. I installed a new MSD coil of the correct resistance. It started and ran noticeable smoother on the trailer, so we went to the lake yesterday. It ran beautifully, on a hot day. Pulled smoothly, idled and restarted perfectly without a hint of loading up, stalling,

A failed coil is tough to pinpoint, but in this case, it appears to be the answer.