My ex bro-in-law did a B Mac a few years ago. Turned out nice. He's a trucker so he wrote the whole thing off.
I have a buddy that is looking for a project truck to do a rollback. Mice and squirrels got inside his motorhome and destroyed the interior. He bought it back from the insurance company with plans to strip the body off and put a old truck front over the engine (which has less than 50K on it) and frame. Old body, new motor/trans, suspension. Comfort and Cool he calls it.