All of the years are great trucks and will give you years of service. 06 and up you get the 6 speed allison which can take a little bit more abuse and have an extra gear which is always nice. The newer trucks like lmm and lml are great trucks but you have more emissions stuff to get rid of to be truly reliable in my eyes. An 06 lbz would be a great choice in my opinion. Keep up on your maintenance , run an additive in your fuel, and change fuel filters religiously and you will have no problems. As far as mods that all depends on your wallet size...or credit line:rofl basic mods would be exhaust, intake, efi live , and lift pump. Built trans if your running big tunes and plan on it lasting long. Tuner is your choice big names are kory willis, idaho rob, nick at duramax tuner, ridge runner, and caleb at blackout performance in no specific order.Use the search function on here and you will have enough info to read for days, months, probably years. Welcome to the forum, stick with a duramax and you'll deliver your campers long before your dad

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