The BSFC looks good I would look at the spark plugs and try richer first and then leaner second to find out what the motor really likes as far what that O2 systems reads OP, Did you try higher RPM before stopping the dyno tests? If not I would have
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
I would look at the spark plugs and try richer first and then leaner second to find out what the motor really likes as far what that O2 systems reads 
