vacuum advance

[daveblissett]

i have built a 2 ltr pinto and the ignition timing should be as follows static timming 16 degrees rising to 38 degrees at 3600 rpm and above
i can sort this bit out but my question is about vacuum advance for example when the engine is running at 4000rpm with the throttle wide open the ignition timming will be 38 degrees but when i close the throttle should the timming advance to 53 degrees ( i have read that 15 degrees for vacuum advance is a good starting point)
or should the the timing never go above the 38 degrees "all in"
thanks dave