So, what I have is a fully rebuilt 261, which I have already done the 20mins @ 2K RPM break-in run. Following this, I had trouble starting it, as I found a vacuum leak after I removed the vac gauge I had on it. Now I want to readjust the timing and the carb as well.

Since I have a flywheel off of a 216, I don't want to go by the markings on it and instead use the vac gauge to tell me where it needs to be. I found that max vac of 24lbs was WAY before the ball bearing(to the right of it), which I believe means retarded? I played with the throttle adjustment and fuel/air needle (which I honestly can't tell where it sounds best) and this is what it sounded like:

https://photos.app.goo.gl/wd1z6D75ZqB87y4r8
https://photos.app.goo.gl/PHQdjydD6jq7skrGA

I turned it off to try starting again and it wouldn't fire at all. I adjusted the distributer clock-wise to where it should be 5 degrees before the ball-bearing and it will start and run, but it's around 20lbs of vacuum. Should I ignore the highest vac and just keep it in this general timing? Also, what should I be looking for with the fuel/air adjustment and what is a realistic RPM, as I believe the manual for this engine (1960) says 450RPM. Thanks!

1948 Chevy Thriftmaster 3/4-Ton
Poncho "farming" in Ontario
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