Super tuning car runs good shooting for great

The 'cruise' AFR depends entirely on the engine and gearing.
If it can run 14.9, that's great.
Same advice I just gave the guy playing with an Eddy. If you want to experiment, go as lean as it will tolerate without surging or trailer hitching at high speed steady state.
So with a Holley type carb, that's the primary main jets. When it surges, that's followed by dying, so you need a place where you got some room - not heavy rush hour traffic!
It will usually catch as you let off the throttle, and you can continue on your way, but your speed will be limited to 50 or 55 or whatever it is where the mains fully take over from the ide/transfer.