Hello all, new to Honda world. Came from can am outlander 1000. Bit of a change!!!

Just picked up a 1991 Honda fourtrax 300 in pretty nice condition

Want to do a few upgrades just as brakes first.

I want to install a front disc conversion but every vendor such as highlifter super Atv all list for 1992 and up.

Why is this? I thought they were all the same. Seems like every option I try to upgrade is only for a 1992 and up. The 424 kit is the same!!

Do I have a year nothing is offered for??

Thanks for the help!!