[Healeys] Overdrive Numbers

[jomar healey]

I just picked up a 3 speed box and overdrive.  The trans has the number
981stamped on it and the overdrive has a brass plate stamped 1292/227.  I know
the 1292 identifies the overdrive as a 28% unit but does anyone have a guess
if the other numbers have an significance.  Thanks

Joe
BN1 #923 Coronet Cream
BN2 100M
BJ8 "The Blue Baby" what my wife a daughter have called the car for the last
28 years