The GMC CCKW

Hello All,Can anyone advise if it is possible to jack up or lift up the rear body on 353 H1 dump with the drive line p.t.o. shafts disconected? will it? could it? damage any part? I want to try to raise the rear for sand blasting and dont have the engine to use as motive power I could lift it with a loading shovel,or jack it up slowly with air bags or jacks but Im not sure if I need to disconnect the ram!! Regards Erb

Lift it slowly with the tipper lever in the Lower position, that is fully back.
It worked ok when i did mine.
Alan