I got a dilema and it is not quite Mopar related.The air conditioning in my combine needs to be charged but it is the old R-12 setup in a 79 John Deere 4400.I called the dealer and he said no conversions are available for it.I saw an ad in the farm paper for freon and called the guy.He is down in a lil town in Missouri and sells do it yourself charging bottles that cover a number of types of freon{R-134A R-12 R-22 etc}Claims it is all Fluro Hydrocarbons and works in all systems.Low price on it too,but my inner voice tells me how can it be???????? I,m leery....I called the local Napa store about buying a A-C manifold setup that handles R-12 and R-134A.After he in formed me that R-12 is still available in a 30 lb. container for the "Princley" sum of $1541.00 and you need A-C certification to purchase the R-12.I have boosted my A-C in my one tractor with a can from Carquest that has a guage on it,but that is strictly for 134A only.Was wondering if anybody had any experience with a similiar situation as the guy in Missouri or solved the problem another way.The nearest John Deere dealer is almost 40m miles away and I can see the $$$$$$$ adding up on a service call already.