318 Engine stumble

AJ/FormS said
36@3600 is the same as 36* at 3600 and not the same as 36* at any other rpm..... unless the timing lite says so.

With the Vcan removed, check the timing every 400 rpm from 3600 down, namely 3200/2800/2400/2000/1600. Plot those numbers on a graph with rpm along the bottom and advance up the side. Next connect the lowest three dots with a straight line, averaging up the middle. Then the top two get connected. Then extend the lines until they cross or meet. Now you have a pretty good idea of what your timing is from 1600 to 3600.
There is nothing wrong with 36* at 3600 unless it appears on the same graph with less than 10* at 1000rpm. If that appears on your graph, then yes, you will want to reduce the flyweight travel. Then rev it back up to 3600 and twist the D to get 36* again, then check the idle timing. If it is now more than 10* and less than 16* you done good. If you are targeting a specific idle timing, like say 14 but you only have 10, then you will have to limit the flyweight travel some more, and again retest.
With 36*@3000 timing, you may have to run premium gas to keep her out of detonation.I would not be in a hurry to try and run that.
In a streetcar; You will not likely feel the difference from 36* to 34* with your butt dyno. Maybe your butt-dyno will not feel the difference from 32* to 36* either. This is because the vast majority of the time, you will not be at WOT, and will not miss 3 or 4 or 5 horsepower at 3600 rpm. Your right foot will just drive that many horsepower deeper into the throttle. You would have to have a pretty small engine to miss them. After all; 5/150~3.3% at the low end of the scale and just 5/230~2.1% at the higher end.
So sneak up on the power-timing. Don't be afraid to take several days or even weeks. Get to know your engine and the sound of NO-detonation. Then you will hear, and maybe feel, detonation if it comes.
Detonation must be avoided at all costs.

Vac advance is unhooked. The advance will be limited after I get the total timing in. What vac advance should I go with? I have the msd limiter. I was planning on 14° Or run it as high as it wants until it pings and then back off.

What I have at idle right now is 13°
I had it at 15° and it seemed fine. The timing went up to 38° and I was told that was too much so I turned it to 36°

The only time it pings is when it’s cold. That’s at idle
Once it warms up it’s fine. The choke is not set up yet. It’s about 65°F here when I was tuning with the choke full open. If I let the car cool back down it pings some after restarting it. .....
When it’s cold it runs lean enough to shut the car down when I hit the accelerator. I’m switching to the orange cam tomorrow and that should help. Pretty sure that’s cam related. I’m not worried about that yet. That’s all in the carburetor I’m pretty sure and it’s just running lean on the idle fuel restrictor. I’m working on adjustable ifr and idle air bleeds and will fine tune that.

I plan to run the cheapest 87 octane gas I can find. This car is not for racing or even spirited driving much. If anything I’m after the best fuel economy I can get. I’m running a stock cam, streetmaster Intake and Holley 600 for that reason.

So.......36° at 3000 I need to run higher octane....if that’s the case I’ll leave it where it is. I won’t be doing wide open pulls or anything like that rite now. If I need to I’ll li it the advance plate. I was looking at how to go about that. I can put a roll pin in it and stop it....then file it down until I get where it needs to be.

If I won’t even notice the difference between 36° @3000 and 36° @ 3600 then I won’t bother. I will be in the main jets and transfer system most of the time.
There isn’t much difference in power? Like 5hp?

I did a loose chart on the way to seeing what the total was. I have some moroso advance springs to tune the curve that are coming in the mail tomorrow. This timing and testing today was strictly to see where it was all in at so I could limit it if I needed to. I wasn’t sure what to expect. If I won’t even feel the difference between 3000 and 3600 street driving it’s fine where it is.
I’ll do a better more accurate chart that’s more planned out.what do I want this chart to looks like?