Ok my buddy has an 03 7.3 great truck,,, I have been looking at the 06 6.0 but came across an 03 6.0 4x4 with 21000 miles, and can get it for a great price. My question is, my buddy with the 7.3 says the 6.0 from 03 to 06 had a lot of problems... is that true and what type of problems am i...