The book I have says 1969 production was MY50396-MY50440 and then 1970 production was MY60473-MY60587 for the 3496 combine - grain. The serial number ranges do not appear to be consecutive. They look like batch builds. Unfortunately your serial number does not fit in these ranges but I'd guess it's either 1969 or 1970.
2-A4T 2270 2155 1865 2-1050 Vista 4-1000 955 950 900 G708765 GVIfwd GBD GTA 21-32 5-670 2-M5 302 UG 3-UB 3-U 2-UTI MTA 4-JS3 HL500 4* 445bh 445bbugy 335I ZBE ZAS ZTS JTS/U RTE 2-RTI 2RTS RTN 3-R BG BF V Motrac MT40 MY40 14-Mwrs 2Uni's MEU pu