In the 41 years I was in the lift truck business with 3 different manufacturers - I have yet to see a "factory authorized" conversion kit from cushion to pneumatic - other than on 3 wheel electrics. Once upon a time Clark & Allis-Chalmers offer a "hybrid" pneumatic unit that had cushion steer tires as an option - not a real popular unit..
If there was such a thing as a conversion, it was developed by a "shade tree" & not a professional shade tree (did not want to take a shot at proshadetree a good FAC contributor).
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