We're/I'm just trying to help you to get the idle right, dealing with the symptoms you described. Run on is caused by a throttle plate open too much at idle. (or a vacuum leak)
I saw no difference between 34, 35, 36 degrees total advance. I was not on an engine dyno. This isn't NASA here.
IF you are trying to optimize the engine to the ultimate degree like a race engine is then you need to put it on an engine dyno and play with everything there for optimization.
The Yates heads are designed as only one of the components of a system necessary to optimize a race 351. If that's what you want then you need to run the entire system including 106 or even more leaded race gas. Also it depends on which rules you are running under.
Remember originally the engines had to run under carb size restrictions of I think something like 450cfm. There is where tricky ports and high swirl become more important along with exhaust gas exit angle and velocity.
The cam profiles are also tailored to maximize those features as well but lets just say that typically the valve lifts used tend to be well over .700" lifts and designed for 8,000 something rpm's.
I'm not even sure that kind of an engine is compatible with the concept of a C6, C4 or FMX automatic transmission at all. At that point you need to seriously consider the specs on a Pence cam. A manual trans car can get away with a lot more bad maners stemming from border line cam profiles then an automatic trans car can.
On a street engine with compromises necessary to make the engine streetable, seemingly any of the aluminum heads are worth 25 or 30 more horsepower over a worked iron 4v head. That's mainly due to a much better exhaust port configuration, not a better intake port AND their value wouldn't even begin to show until something like 5,000 rpm and up. Their biggest value is less weight and shinny appearance.
Sure you can, and some have put legitimate former race "Clevelands" on the street with 700 or 800 hp but they didn't stay like that for long and IF they are still in running condition needed to be seriously detuned from those configurations.
They can be run on the street but it doesn't make them good street engines.
If you can't get the thing to idle right with your set up and playing with the timing and carb idle setting then the cam is too radical. Let George write a cam profile for you.
As far as worrying about low idle vacuum, don't waste your time with it. Been there done that. Just install a vacuum pump. You really want 17 or 18 inches of vacuum for the brakes and I can't think of any off the shelf aftermarket cams that can deliver that. Perhaps a Pence profile can?
Loss of engine vacuum too at idle in addition to the cam timing can be from a bad vacuum diaphram in the power brake booster.