From the Novak site I was able to determine that my SM420 4-speed transmission falls in the year range of 64-67 since my transmission # is 3761930.
Here's the Novak tranny ID info:
1947-1953: No ribs on the case, grooved input shaft instead of neoprene seal. Synchro rings all differ from each other. 1st-2nd synchro ring is bronze. Six digit casting number on the case, usually like "59xxxx".
1954-1963: Same as previous but uses a neoprene input oil seal.
1964-1967: Same as previous except 1st-2nd synchro ring is aluminum and 3rd-4th synchro rings are identical to each other. Seven digit casting number usually like "37xxxxx", "38xxxxx" or "39xxxxx".
One thing that puzzles me is that what I believe to be the date code for my transmission reads "J288" which I would think would decode to October 28, 1968. The Novak site states that the last year the SM420 was built was 1967, so is this statement incorrect or is my interpretation of the date code incorrect?
