The GT comes with 3.31, and most people upgrade it to 3.73. That is a mere 13% icnrease.
V6 comes with 2.73, so 3.31 would be a huge 21% increase already. Isn't 3.55 too much for the RPM at highway speed?
If you do replace the gear go up to the 3.55:1 at least. Performance improvement is much better. I hate the way the way the auto tranny shifts. It's weird?
2014 Mustang V6 3.7L 6-spd manual, with MGW shifter, Airaid CAI, BBK shorty headers, Corsa Sport axle back, strut tower brace, JLT oil separator, GT500 differential cover, BG Synchro Shift II gear oil, Redline differential oil.