Timing problem

Good on the fuel system. I'd still get that bad gas outta there. Really bad gas can gum up intake guides badly enough for a valve to stick to bend a pushrod or even break a rocker arm.

Yes 0* is a good place to start. But 8* would be fine too.

Does this engine have a stock camshaft or another? 11" of idle vacuum may be OK for a moderate cam but is waaay low for a stock or near stock cam.

If this is a stock cam, then it looks like you have a vacuum leak. Under the carb, or a bad PCV hose are good places for such a leak. Or the intake manifold. Did you change that?

If you can't figure out how to use the dwell meter, use a feeler gauge to check the points gap at max opening. It'll work fine; just make sure it is checked exactly at max opening.