The frame number on my young bloke's latest project is RC11C-******. It being watercooled with a Full Floater rear ended RM80. Going by the Part Listing, it was much the same for the models from 1983 to 1985. I believe 1982 model had the same frame and crankcase with the aircooled top end. I read somewhere that Suzuki changed the frame number prefix style with the new design, but I can't remember where. Try Googling your number, I'm pretty sure that's all I did. I hope this helps, Micheal