My '07's rotors are originals with 32K on them and brakes are great. I live in the western part of Virgina and the truck was originally sold in Waynesboro and the OO lived in Salem and I found it at C-burg and now it's back near W-boro.

Point is .... NOT FLAT country.

I do use that button on the console to kick it out of OD on long down hill runs or when coming into 45 zones from a 55 zone. On steeper WVa. type grades, I'll frequently drop speed and bring her back into 2nd from 3rd.

I rarely need brakes in dring these hills, but if I left it in OD I'ld sure use them a lot. My '77 has about same rear gear with 3.50 where as the '07 has 3.55 gears, but the '77 does not have OD 4th so when you let up off that, it slows.

As to the plugs, I'll get the tool and plugs and do that by 50 K.