Hello Hawkeye58.
Welcome to the forum.
You will find a lot more info here then you ever would at that other site
The 92 - 93 KX500, KX250, and KX125 all used the same Blue forks with the same external measurements and shared the front brake, front wheel, triple clamp, ect.
The problem is, when you go to the newer forks, the increased in diameter as well as they changed the front brake mounting holes.
Also, the bearings were a different size for the triple clamps.
I know some guys on this site have done it but I believe they had to have a different stem pressed in the the triple clamps.
You can reuse your front wheel but everything else needs to be changed out.
You might want to start with the search button on this site as I'm sure there is some info.
And, hopefully some people will chime in who have done it.