Thanks Lemans Guy.Lurching or trailer hitching is often a symptom of too much advanced timing,... turning the timing up at idle just to get a smooth idle is a mistake ......without knowing the rest of the story.
These cars will run great at in a range of numbers including 24 degrees of timing at idle generally, but you must be grabbing at least 10 of that from vacumn timing.
If not and your base timing is 24, your centrifigal timing must be 12 or so. Most distributors are way over that, so make sure too much timing will cause detonation.
Don’t just turn up idle timing until it “Feels” good or “sounds” good,.....it should feel good and sound good and be correct throughout the power band.
You can make it feel and sound good at idle,...and it will lurch ping and detonate throughout the power band.
So make sure.
Logic would dictate that if I have some low speed lurching and no pinging and within 36 degrees total timing, that I should be able to pull the vacuum advance off to stop or minimize it-no go.
So I'm going to continue to retard the timing to see if I can time it out. My car is amazing in that I can't make it ping but can get to that other warning sign of a strained starter on startup but she still lurches:x.