You can look at this site and at the bottom it tells you the mount specific to the year. This will give you an idea of what should work as far as year.
Here is the text from Viper that shows the different years that their specific mounts fit.
Foreman - MA11905
- 2002 & older TRX 400 4x4
- 2003 & older TRX 450ES 4x4
- 1998-2004 TRX 450S 4x4
Foreman - MA11911
- 2007-2011 Foreman models
- 2007-2009 TRX 500
- Please Note: Max 3000 will not work as the terminals interfere with the frame - all other sizes fit
Foreman - MA11914
- 2005-2006 TRX 500 2x4, 4x4 - Manual & ES
Foreman - MA11920 - COMING SOON