I've got my stock radiator laying here, it's a 3row copper/brass, I've checked all the local shops to see if they could get a 4 row core, all said no...
No, feeding oil through the fill tube would do little to nothing. The place that needs oiling is deeper towards the crank area.
I'll have something to show in a few weeks, parts are being made and I have cut a cover to be able to see and video what my idea is and does, it won't be on a running...
You can call them and they will warranty it... I would need the purchase date to start a warranty. Either way you would need to know the purchase date...