I had the problem with a hood - oil canned it good trying to get undercoating off the inside that the previos owner had sprayed on it. I have also looked at several Chevy trucks from '34-'36 that had hoods and doors sandblasted and they were all warped beyond saving.

A local powder coater also destroyed an electrical cabinet we sent to him to have powder coated. He sand blasted the heck out of it and the doors and sides balooned out almost like he had pressurized the enclosure from the inside.

An AD truck has lots of compound curves that hold their shape well - blasting the bed sides and top of hood would be the most likely to create problems if you got carried away at all.