A 520 modified by Perris Valley into an actual motorhome is for sale in Washington state. Don't believe that it has run recently, if not for decades. Considering buying it and driving it home (2800 miles), but it will need to be prepared first, if this is even doable. It does not have hardened valve seats, so either a lead addative or cylinder head work needs to be done. Complete brake overhaul and clutch hydraulics, for sure. New tires. Rubber hoses and things. What else?Wikipedia says the 520 can carry 2200 pounds, while the 521 is set up for only 1100. Something wrong there. This truck is way loaded down with the camper. Eventually, a Nissan dually axle would be fitted. Can airbags be installed? How about swaybars. This thing surely needs all the suspension help it can get! An L engine transplant would be a good idea as would disc brakes. Are regular maintinance and repair parts available? Imagin you were going to do this. What would you do? Driving it, as opposed to trailering it or shipping it, would be part of the adventure. So would be bank deposits and creditcard payments s s s s s.Thanks for any imput!