OP can search til blue in the face on this. Not really a new question!!
One thing to consider whether you want def or delete capable truck is you pretty much can't get the new chassis Ram without the def system.
Someone help if you know for sure but all 14 and up are new chassis def emissions and all 12 and down are 3rd gen chassi with dpf only.
13 models are still old chassis or did 3500s get the new chassis with no def? Imo that would be the truck to find if you wanted to delete it, otherwise get a 14-up and a jug of def. No big deal, they run fine and are solid trucks all around.
By Tthe above post, I was wrong. If 13s are old chassis and def then no reason to get that one. Get a 14 with the newer chassis.