Re: 390 Timing setting
If your engine is stock I would time it at 6deg BTC and add 2deg for every 1000 feet above sea level.
If it's not stock and your running a large cam, you'll have to adjust timing for best results. For example: if it pings at high RPM's you'll need to retard the timing untill ping goes away. Anytime you run a Hi-po engine, your variables change with the weather....hot, cold, rainy, dry, humidity....if your like me,
I have to adust every friday night for cruise night, cause you never know when a Z06 is gonna want to try his luck!!
Alaways start with stock numbers...then adust from there.