If you want all surfaces painted so that you never have to worry about rust through, do it off the truck. Sometimes, things look harder than they really are. You can paint the inside on a table, or whatever, flip it over and do the other side. KNOWING you dont have any surfaces that could rust because you didnt address them.
I feel your pain. I even went to the trouble of making a jig to hold the door, fender, hood, etc. If you look at some of the TV shows or even youtube, you will see they use foldup fender frames alot. Its because you just cant get to alot of the fender if its bolted on the truck. To do it right? NO.
