What is the vacuum on the advance line at idle? It should be zero until the RPM is raised slightly. It sounds like your distributor vacuum line is connected to full manifold vacuum, not ported vacuum.

It's possible you have tightened the linkage up too much and locked up the advance unit. You should be able to turn the distributor housing CCW with the engine stopped and the spring inside the vacuum advance will return it CW when you release it. Forget everything you know about Brit cars- - - -a stovebolt distributor is SUPPOSED to move!
Jerry



"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
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