I am not positive but I think the last year for the CB900 was 1982, 1983 CB1000 and CB1100, 1984 was the first year of the VF series.
If it is a 1982 CB900F it is the same exhaust, at least my 1980 CB750F and 1982 CB900F use the same Delkevic 4 into 1.
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