I recently had my 13 auto on the dyno. With Bama race tune, x pipe and Shelby GT 500 exhaust. It only put down 346 RWHP and 362 RWTQ. The tuner then installed C & l cold air (tune required version) and put in a new dyno tune. After result were 371 RWHP and 391 RWTQ. Good gains, but not where they should be. Most other 5.0s this guy has tuned are well over 400 RWHP. Interestingly, we pulled the run files for 3 other similar cars side by side with mine. One was a buddy's car who was with me. My car was putting down a better torque number of 391 then all the others. However, all the other we're 400 plus on RWHP and mine only 371. Also, at 5000 RPM on my dyno sheet, on both the Bama tune and custom tune, power and torque nose dive. He seems to think I have a weak tune file from Ford and/ or a throttle issue. He recommends putting by stock box and tune back in and taking it to Ford to have them update the firmware, then bring it back to him. Any thoughts opinions would be greatly appreciated.