Changed out front rotors and pads on my '07 yesterday. I must give GM credit it was a painless quick job. My question is this, why are there 4 different brake codes on the '07 and only 2 different rotors and only one set of brake pads? It doesn't make sense to me to have different size rotors if they are using the same size pads. I would understand if one set of rotors were cross drilled or something but the first set I got were 11 22/32 (or something like that) and the set I needed was 10 7/8 but both use same set of pads. No difference in thickness as far as I could tell.

 

I believe that the pads may be the same, but the overall diameter may be different since it accounts for the 2.2L, 3.5L and 3.9L if I'm not mistaken.

For example, check the measurement diagram between the two engine models:

Premium Dimpled and Slotted Brake Rotors

Premium Dimpled and Slotted Brake Rotors

Thickness is the same, but the diameter is different. Might be for additional cooling capacity to go with the bigger engine.