Thanks everyone, I did do the chalk test. 55 psi was over inflated. Tires were hot at 50 psi when I did the test, and next morning the cold air pressure was 45 psi. When it stops raining, I'll double check.
Since the manufacture keeps both tires at the same psi, I'm doing the same.
The front tire came out pretty much perfect with even wear on the chalk all the way across from driving in a straight line. The rear tires wore even all the way across to 3/8" from the edge of the tread. That 3/8" tread still had dark chalk while the rest was wore.
Since the tires are at the same pressure, show good even wear, and ride, vibration and noise seems to be still good, I'm going to leave it there. The rear axle isn't loaded with the trailer or gear right now so it will likely wear better when loaded. BUT I'm going to keep them at the same tire air pressure as Ford does that with OEM P series tires and the LT option LT C Load tires.
I guess the E load Tires may wear a bit different than the C load tire.
