Ya' might want to find out whether or not the roof and doors are integral to the structural integrity of the truck before you start chopping stuff off. I really have no idea, just a thought.
He's right. Y'all should probably weld the doors and use the Dukes of Hazzard style of entry/exit. You know, for safety.
Seriously though, those are the models that had the seatbelts integrated in the seat itself, yes? You should be alright. Of course, given the hijinks this thing is liable to see (
) they won't provide a lot of safety in case it winds up on what used to be it's lid.
Better than a milk crate and a ratchet strap, but still, be cautious.