Well from expierence and trial and error I’ve determined where my engine likes the initial timing and the total timing and mechanical advance settings.
It likes 14-18 initial 32-34 total, and now that I have a distributor where the rotor phasing is within range, I’m basically left with figuring out the correct advance rate and the correct amount vacuum advance.
I know my engine prefers a slower advance rate, because when I had the mechanical advance set at 16 degrees that made the advance rate all in at 2400.
There was a rough spot around 2400-2500, it was suggested to me by a couple different knowledgeable guys that the rough spot was the advance rate coming all in a little too early.
Instead of tearing the distributor apart and swapping springs, I decided to ncrease the mechanical advance to 20 degrees because that slowed the advance rate down to be all in at 2800 rpm.
In turn I had to drop my intial timing down 4 degrees, from 18 to 14.
The rough spot cleared up quite a bit, which tells me it likes a slower advance rate.
I’ve been doing some research onthe magnum engines and have found that they don’t require as much total timing with vacuum advance because of the better chamber and that they don’t like 48-52 total degrees timing while cruising down the highway, I’ve learned they like a small amount of vacuum advance like 10-12 degrees for a total of 44-46 degrees while cruising with vacuum advance because of the more efficient chamber m.
So I think once I limit the vacuum advance it will clear up and be happier.
But it’s going to require a little more trial and error for sure.