as one advances the intake installed center-line, does the engine usually want more or less ignition timing? i know this is a pretty generic question but there should be a sort of rule of thumb.

Timing is about the efficiency of the heads... but
if they are at the max pressure they can support before
they detonate then yes as you move the cam timing
more advanced and build more pressure then the spark
timing would decrease

thanks for the input mr.p. makes sense since advancing it increases cylinder pressure, with all things being equal.