The only reason the LLY overheat (I live in Alabama and mine has ne'er overheated but whatever) is the **** mouthpiece they came with stock. Get a 70 part in the LBZ mouthpiece and solve the problem. I do wished mine was an 06 because of the 6 speed but I haven't had any problems with mine. EFI Live+Duramax=badass!!

 

ive got firnds with all years... all have been good, i think your question should be more aboout which one has problems once modified if you looking to go down that road..

Keep in mind ever few years gm bumped the hp and torque of the trucks, so im guessing a newer truck would be like older truck with a programmers..