A QUICK QUESTION ABOUT MANIFOLD VACUUM
There's no load. You can't use the numbers from no load to do much more than getting a sense of what the engine is like.
a. With no load engines will love lean mixtures and lots of advance to match.
b. At idle rpm the engine makes relatively little power. Any load at idle is a relatively heavy load for the engine. In other words at 650 rpm its a big jump percentagewise from freewheeling to placing in drive.
My sense from what you've posted is that your engine will work well with timing curve like Chrysler used to use (production) or Mopar Performance put in their distributors that were made in-house. Either will be a good baseline, then adjust/tweak as needed for fuel and other conditions.
Example here as Rick as he works through and posts the effects of his changes
And an example of how that changes a bit with different combustion characteristics
I kindof spill the beans on shaping the curve here
If you are stuck with a distributor advance that can't or shouldn't be shaped (eg MSD distributor) then use a manifold vacuum port at idle as a work around. I think your engine will have steady enough vacuum at idle to do that. But if you run it lean at idle, then you will kill it when going into gear; rpm will drop, vac will drop, and manifold vac advance will likely drop causing rpm to drop...
There's no load. You can't use the numbers from no load to do much more than getting a sense of what the engine is like.
a. With no load engines will love lean mixtures and lots of advance to match.
b. At idle rpm the engine makes relatively little power. Any load at idle is a relatively heavy load for the engine. In other words at 650 rpm its a big jump percentagewise from freewheeling to placing in drive.
My sense from what you've posted is that your engine will work well with timing curve like Chrysler used to use (production) or Mopar Performance put in their distributors that were made in-house. Either will be a good baseline, then adjust/tweak as needed for fuel and other conditions.
Example here as Rick as he works through and posts the effects of his changes
And an example of how that changes a bit with different combustion characteristics
I kindof spill the beans on shaping the curve here
If you are stuck with a distributor advance that can't or shouldn't be shaped (eg MSD distributor) then use a manifold vacuum port at idle as a work around. I think your engine will have steady enough vacuum at idle to do that. But if you run it lean at idle, then you will kill it when going into gear; rpm will drop, vac will drop, and manifold vac advance will likely drop causing rpm to drop...