So, i finished the rebuild of the 2002 EC 300. (Short write up coming in the "what did i do to my GG today" thread.)
Anyway, i installed the ebay radiators. A few things.
1. Hose mounts are larger diameter than stock. I had to work a bit to install the AC3 radiator hoses, but they fit.
2. Crossover tube between radiators was a bit tricky. i had to buy hose at NAPA 'cause the AC3 hoses wouldn't work. (only downside is that the red hoses were replaced by black, but you can't see the crossover anyway).
3. Radiators hold about 500 cc more coolant than stock. i never put more than 1L in the bike with old radiators, but the new radiators took 1.5L.
4. No leaks.
5. Had to use a different radiator cap. I used this which is better than the temp sensor on m TrailTech Vapor, which i can't read with old man eyes:
https://www.ebay.com/itm/143751924762
6. CRD radiator braces for the old radiators fit the new radiators.
7. Radiator/exhaust pipe clearance was the same.
SO, for $84, I'd buy again. The old ones were 19 years old - these should make it that long as well.