thatblue_67stang":167ypoq4 said:
But also wouldn't the mechanical advance and boost retard work against each other.
Look at it this way.
No matter where the ignition timing is when there is no boost, as soon as you increase manifold pressure the timing needs to retard at that point.
Since I don't know how much mechanical advance your distributor has, it is more important to check total timing without the
vacuum advance hooked up.
Rev the engine till the timing stops advancing and I would suggest that the total timing be at 34 degrees BTDC at that point.
I would not run the vacuum advance till everything else is sorted out including the carburetor tuning.
You don't need the extra variable.
Most everyone starts with 1 degree of retard per pound of boost at the boost timing controller