Can you explain why that would be and why it's not just the same thing as the range from the Factory?
Factory should not pull 9 deg timing on 91 oct, or depend on timing pull to "compensate" when you use better gas.
For custom tuning, it is acceptable to pull timing via KR, but you are almost always leaving a lot of power on the table when you do so. Tuning so you have 0 KR timing pull will always guarantee the best power/torque. Stock KR based ignition pull is very conservative, and tweaking KR to be more aggressive is kind of unsafe unless you have detcans to tune it.
Instead of just pulling timing on KR (to provide MORE timing when you have better gas), consider also adding fuel via LAMFAWKR (which, like LAMFA, is disabled in most stock files). Instead of pulling 9 deg on bad gas, you may be able to get away with 3 deg or less.
You'll get better results with both bad (and good) gas.
YMMV, of course. I could be wrong about all of this.
