I had my gt dyno tuned today with the sct, jlt and slp lm's and my a/f came out at 13.4 across the board. I questioned it thinking it was too high, what damage will it do if I don't have them change it? They are suppose to be very experienced with the sct tuner.

 

Why do you think it's too high?

And where was the reading taken? With a tailpipe sniffer?

 

Not bad for a naturally aspirated engine. Leaner is meaner and that's not over the top by any means. 13:1 is ideal for a N/A engine.