chansey, throwing my $.02 in this my help get your a/c going , if its near power you could put a couple of halogen lights on the block for heat, to help evaporate the moisture out of the cyls. once you pull the injectors, or pull the valve covers off and wedge the valves open with screwdrivers ,and take the intake loose so the moisture has a way out, I have had real good luck with Marvel Mystery oil , here is the TWIST! Heat the M-M oil in a pot before you pour it in, get it as hot as possible , I usually heat it until it flashes on fire, then put it out and pour it in. I use a funnel and a piece of hose if I don't pull the injectors so I can direct the oil into each cylinder, this works really well. I have a 118b Galion grader with a UD-551 Ihc engine, it sat for seven years with open stacks, it was stuck like chuck, did this trick ** through the valves, by the way** she runs like a champ know, hope this might help you ,, good luck