HELP---have fun guys.

After dealing with cancer, 2010 and 2013, hopefully going to be O.K. it is time to order a new truck. The weight of a triple slide and towing up to 12,000 lbs. boat or trailer etc., is calling for a 550/5500 cab chassis. I would like to put a flat bed with boxes for storage. I am torn between gas/diesel. Of course the diesel would be needed with that kind of weight but I am tempted to go gas and know I would have to tow less weight. Apparently there is something to be said for either, both pros and cons. Let's put our minds/experience together and see what we can come up with. Thank You very much in advance guys. Louie

Diesel! You will need the power if you tow what you think you might be towing. Diesels do not crawl up hills holding up traffic behind; instead the diesel basically flattens the hills. Drive both and it becomes evident which has the best power.