Wanted: Engine number to production year cross reference

[SaltyDog]

I recently picked up a spare Venture engine that was listed as a 1983 Yamaha Venture Royale XVZ12TDK. I am curious if this is the true year of production. The motor number is 31M-002788. Does anyone know of a online cross-reference for the Venture engine numbers to production years. The number range for each year would be really helpful. If someone has a bike with an engine that is close to mine would be useful also. I have searched this forum and others for a cross-reference and various online search engines without anything useful popping up. Thanks for any help..

[Dano]

My 84 is 41R-001262. Matches the serial # on the bike and it was manufactured 10/83. I think the first number is the year.