Radiator heater hose fitting

[JR1]

I also posted this in blazers, because it's in a blazer but could be a truck radiator, sorry if I broke any rules!
Hello, working on 75 blazer, dont think radiator is stock, on passenger side from top down it has filler neck and cap, then overflow hose, then a heater hose fitting, the fitting appears to be plastic and screw into radiator then hose clamps on that, the plastic fitting is leaking, im hopping I can get a new fitting, not a new radiator, anybody seen this, i asked at oriellys and two shops, they didn't know, they didn't seem to sharp though. Below those three things are two transmission cooler lines, and then the main radiator hose!