There's such a thing as being TOO picky. I'd use some fine thread Grade 8 bolts and nuts, fabricate some 1/2" thick backing plates to fit inside the frame, and get out the long-handled wrenches. On a frame that size, being concerned about a little wear is sort of silly. I'm going to assume the truck isn't going to see max gross weight loads often, if at all, right?
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!