6395 pcm with BHDF with 7.4 in 94 suburban with lightly modded 454.
there is a table CTS spark advance compensation vs vacuum vs temp.
that one seems straight forward as it adds a bit of spark when it is cold and takes away a bit of spark when it is hot. However it seems to be tied to the parameter coolant spark bias. It comes stock with a number of 20 in the selection. I have my total advance set to 41.8 and if you set the coolant spark bias to 0 it pegs the advance at 41.8, if you set it at 10 the advance runs about 36 and if you give it the least amount of gas it pegs the advance at 41.8. Can anyone shed light on that parameter. As a side note at light throttle the motor loves the high timing numbers.