Motor is seated and ready for it first 1/8 mile stomp

At that DA, you can take about 12-14% off the ET and add the same to mph for a sea level comparison.

6 steps of jetting? Why? That's a huge step and at altitude may be a hinderance. What did you see that prompted the step up.

I don't find total timing using the plug strap. At the strip, it's always by what the engine wants via best MPH. Pump gas is really hard for tuning via plugs anymore. If it's pinging, you likely need better fuel. IMO, that engine should have no less than 30* total timing to run well.