I have 5 lug with 17" alum wheels. I was told the dif is different, and many of the suspension bits (bearings, steering, brakes etc.) are HD parts. Since I have had to replace very little on this truck I have not had to really get in to it all that much. I did a complete brake job with rotors etc at 80K. I had to give the parts counter the vin but all the parts fit no problem. I will be doing rear axle seals and brake pads this spring (when the seals go your e brake pads get coated in diff oil and stop working)
The biggest repair to date has been a pitman arm and Idler arm and a belt tensioner and roller. I think rust will get the best of this truck long before it mechanically dies. Some times I miss my cars and trucks with rear main seal leaks. They were great at keeping the undercarriage rust in check.