99 7.3 what should I look for?
 

So I am in the market for another truck to DD my friend owns a car lot and has a 99 F350 auto for what I think is a decent price. Truck currently has 196k runs great but since this will be my first diesel what are problem areas? Heard the auto trans is not so great I won't be using it a lot for towing. Me and my son have quads and my current truck is a short bed and sucks it's a 2001 Ram1500 and is horrible on gas. Had smaller trucks mostly Toyotas and want to stick with a full size and need/want a 4dr. I don't plan to mod the truck unless it will increase fuel economy. Any and all input would be great.