I'm trying to do some work with the spark advance for my 383 w/ 16197427. When Idle Spark is active, I can watch the advance fluctuate randomly between 19 and 27 degrees. When I disable idle spark (increase min temperature to max value), it stops fluctuating. Is there anything wrong with disabling Idle Spark permanently and just running off of the Open Throttle spark table? I have identical values in both tables anyway.

Also, I have been searching but I haven't been able to find some guidelines for tuning the spark advance. I started with the SA table from the chip that came with the crate engine. As I have been driving and tuning the VE tables, I have seen knock retard here and there in the datalogs. Do I just reduce SA in those areas where knock retard is happening until it goes away? In areas with no knock retard, is it viable to increase SA until knock retard is seen, then back it off? How do you guys go about tuning SA?