So very stuck...

R3N0 said
Okay, so first off I want to start this by saying I'm not asking to start an argument about which is better "ported" or "manifold". So let's not do that seen to many.

My question: when ported does the motor only use the amount of advance needed? As in when the motor is pulling say 1800 rpm does it only use the amount of advance needed at that point or does it try to use all advance regardless?
So if I turn my can all the way up as the advance comes in will it only pull the advance it needs or will I get the max 15*(on the can) the moment vacuum starts pulling?

My truck really likes the ported side, but I have kept it at its minimum of 8* to be safe and not get pinging. But that means at cruise I'm getting almost 30* should I attempt to push it till it pings and then back off a couple of * on the can?

Let's keep this simple
If your engine likes the advance operating from the "ported" carb connection, keep it there.
Some engines like more initial timing can and are connected to full manifold vacuum.
Do what works for your application there a no hard fast rules.
It will be a happy balance between the VA adjustment and your all in timing set buy the distributor.
For example the VA adds 10* advance on my 340 operating on ported vacuum.
My all in mechanical timing is 34*
So 34* + 10* = 44* at steady cruising speed while the engine is producing 11 inches of vacuum, no ping no knock under acceleration or cruise mode.