Adding to the clearance between the axles (front and rear) helps a lot when driving off-road, crossing a berm, log etc. I dented my fuel tank that way and have seen a video of a deuce trying to climb a 2-ft wall only to get hung up on the fuel tank.
His ideas are not all bad, The truck probably runs well and with the "erector set principle", these mods are easy to reverse if all the parts are still around.
Look at the avatar to the left,

, it's a mil spec M35 k-boom with a deuce bed (from an M756) with the hydraulic tank in place of the spare tire. May look different, but is all okay IMHO according to the "erector set principle".
A Nam-era gun truck uses more non-standard deuce parts and I think a bobbed deuce is a much worse "sin".