Mike, the 'info kits' aren't speculation or marketing, they're information from the manuals of the years collated by the historical dept, pretty much the final say on factory documentation .... that said, it's also the case that there were variations from the general set, depending on the stock on hand and the particular situation at any particular plant, it wasn't unheard of that some excess from a previous year was used because it was excess to service spares needs and what was supposed to be used was short at the time .... I have seen reference to the 261 being used in 63 K trucks until stock ran out
Bill
