Originally Posted by Lutz
The year of KX will determine how easy the swap is. The 43mm KX125/250/500 forks from about '91 to '95 (double check exact years) should slip directly into your triple clamps. A complete front end - including the triple clamps - from any year KX500 should be a direct fit as well, as the head bearings and stem length are the same; some years of KX500 used 43mm forks, the last I believe used 46mm.
Thanks Lutz!! That was exactly the info I was looking for as I scoured craigslist!
I am thinking of just buying that KLX351 in the flea market - he's selling for $1,500 and my similar bike over here could fetch 6,000 with 50K miles!!