Hahahaha OK That makes more sence. YUP not being able to edit a title, or edit a post after some predetermined continuum of time has bit me in the @$$ more than once.
That said,, the base calibration of Holleys (straight out of the box) are figuring average signal of a mildly modded motor (fits the bill here) operating at sea level to about 2500' of altitude. This keeps Holley from getting in trouble by selling carbs that are lean, and burn pistons, exhaust valves etc. so it doesn't detonate it's self to death. They wouldn't sell many carbs if they were ragged edge and 99% of the hobbiest destroyed their motor because of a lean tune. So you can 'usually' expect the cruise and WOT to be pig pfhat at most everywhere else that doesn't see density altitude of near '0 ft'
Reading plugs is better than nothing, but my 40 years of calibrated 'plug eye' and tuning for best MPH at the track,, has learned one thing... my calibrated eye is NO MATCH for a good wideband O2 meter and some sort of data logging.
Here is what is probably the BEST tuning tool you will EVER spend your $ on short of a day on the engine dyno.
AEM WB kit But I don't believe it has any logging capabilities
Innovate LC2 will let you connect to a laptop with a comm port and you can log that way, or with any data logger with a open channel . The original LC-2 was quite problematic,, and i have no idea if they have have the 'issues' corrected or not. But the people at Innovate are sure good to work with.
I harp on data logging because... I don't care WHO YOU ARE you can not drive / race and watch gauges. I have a tach, h2o temp gauge, trans temp gauge, volts, and oil pressure in my car,, but honestly I have no idea why. From release of the transbrake to pulling the chute,, I never look at a stinking one of them.
You can't monitor a O2 gauge and drive.