We've been using ez-off on names on boat transoms for over 20 yrs.... not much call these days, as most names are vinyl, as opposed to brush.. but that is over gelcoat...
op, your gonna have to prime the truck anyway.. get a DA and some 150 to 180 and go at it.. you'll be feathering back bad areas under the rattlecan anyway...
chemicals, thinner, ez-off, etc can cause more work than just ripping it with a DA in the first place... your still gonna have to sand it and sometimes strippers leave the remaining rattlecan stuff soft in areas, thus they sand like chit....
rip it, blow it off, denatured alcohol, mask and load some urethane primer on...