So very stuck...

My timing itself is set. I'm working on how much timing I can pull from my can, but was wondering if because its ported, does that mean that the vacuum signal the can receives is variable... does vacuum movement control how much advance is added. The more the blades open the more pull the can sees, so adding timing as it goes. If this is the case I can just open the can up to 15* and the motor will only use what it needs. I rarely see over 2200 rpm as at highway cruising speeds I'm doing 1600 and passing maybe 2200 if I'm really on my pedal. Doesnt take much for this truck to move now.

If this isnt the case and timing comes in too soon then I'm at 22*(initial) + 15*(the can) almost immediately. Seems like this isnt the case or doesnt have to be.