Just sold my Grand Slam last month. Best method for the buyer:
1. First emptied all the loose stuff, including the heat deflector, grates, etc. (my custom grates weighed 20 lbs).
2. Used a mini van with the back seats folded forward.
3. Two guys of young but average build
4. Rolled it to the open back door, tilted it top first into the van (protected the bottom with a blanket) keeping the lid closed I think with a rope around the body. Then slid it on its back into the van.
I think you could do the same with a pickup but it would be higher up to lift as you tilt it.
I don't think it would be lifted with one average guy, just because of the size, clumsy. I don't think keeping it on its wheels would be wise.
Another suggestion, might be to lay it on its back and remove the legs. then it could remain upright in the truck. Again requiring a good deal of protection with moving blankets or the like.
Or are you just taking it somewhere to cook with and return home with?
??