Stock Koyo??
 

My motor has been pulled for porting and while I was looking around in the engine bay, I noticed that my stock radiator says Koyo on it. Are the std rads made by Koyo??

mine doesn't say that!

maybe it's not OEM? Did koyo every make an OEM replacement for the FD?

I remember my Skyline had a "calsonic" rad stock on it.

^ I know the s13 I sold last year had a clasonic sticker on the stock rad. I would assume the radiator is stock based on the plastic parts.

I imported the car from Japan and it did come with minor mods on it (exhaust, intakes, suspension) so perhaps the previous owner installed it but it does look completely oem.

Koyo makes a lot of original equipment parts for various manufacturers.