Hi Blue,
The 55 second series and later have straight frames from front to back as viewed from the side and they are also wider that the AD trucks. The AD frames go up and down a little as viewed from the side. Sounds like a big job to swap for a newer body style. There are a lot of AD trucks around here, but if they were scarce, I would take a cab off of a 1-1/2 to 2 ton truck to use for the pickup. Here the pickups were pretty well used up, but the grain trucks were only used a few times a year at harvest and then were put up in a barn. Just something to think about.
Ralph
