How to tell what MY from exterior.

[sanctified]

I'm working on getting a 6.0 and since I have been looking they are everywhere. The problem is I can't tell what year they are. I know from the badges the 6.0 's, 6.4's, and the 6.7's. Those are easy. I can't tell the difference between like an 06 from and 04. What are the subtle things to look for on the body that tell what year it is. This will my curiosity as I continue to drool over man trucks until I can make the purchase in another month or so. I am specifically interested in the 6.0 years.

Thanks.

[kingranch89]

grille, headlights, bumper, the badges are different, one is leaf sprung the 06 would be coil over very easy to tell the difference in my opinion