Torque readings on dynos will show the multiplication of the gearing in the car. For example (and not accounting for frictional losses in the drivetrain), if you tested in 4th gear which is a 1:1 ratio, and the diff is say a 3:1 ratio, then an engine putting out 100ft/lbs at the flywheel would show 300ft/lbs on the dyno. Some dynos are configurable for gearbox and diff ratios so that the results are correct.
I reckon you should get your tune sorted out as lean = bad especially in hot weather - not a problem where I am