I have them on 3 bikes.
2011 RMZ450 --- DoubleD had cartwheeled this bike nicely smashing one radiator before selling it to me. I immediately put the chinko units on and have never riden it without them. They are fine except the right side moulded plastic OEM louver didn't fit well and I had to zip tie it.
1989 RM125 --- Generally fit....had to drill out the mounting holes for the plastic louvers to actually go in them. The one hose spigot was strangely larger than the others, not sure if this was a goof on my set or what. I've never even started this bike.
1992 RM250 --- Fit fine, same louver issue as above on 1989. Not a big deal. Everything else fit fine and I've raced the bike several times, no issues.
I have also sent 1991 RM125 radiators to Mylers for repair and they came back like new. But it cost more money.