Im looking at my basemap, and I was concerned about timing being too high. What is the maximum timing for roughly 12:1 CR, GSR with S2S2 cams at cruising 3000-3500 rpm at around 14-17" vacuum columns.

Mines is at 35-40 degrees

 

That's within reason.... at 17" you aren't under much load so the chance of causing damage is very minimal. Just try to get good tip-in response in this area and keep your a/f dialed in

 

That should be just about right. With my 10.6:1CR H22 at -14" I'm running about 38* @ 3900rpm

 

Seems about right... I run 44* on my stock Z6 and 43* on my boosted LS in the cruising speed columns. Really helps out with MPG and actually quiets the exhaust down if you can lean it out to ~15.5:1 AFR.

 

At cruising 70 mph my AFR is about 16.0-16.2:1
Will adding more timing lean it out even more?

 

YES

 

that is a little lean. honestly id rather run a tad more timing at that afr on a LOW load setting than too little timing.

i run mid 15's afr while cruising and between 38-42* timing

 

Timing numbers will vary greatly, depending on what EMS you're using.

 

also true, i know from experience i can run cars a few tenths of an afr point leaner and with more timing smoother on neptune or s300 than i ever could have pulled off on uberdata or crome free for that matter