Another overheating situation 63 Slant six

Hi Guys, its been a long time since Ive been on here, been trying to get stuff done but my old body is just giving me fits and its getting harder and harder to do anything on the girl now a days. Heck, harder to get anything done now, hands arthritic.

So here is my problem, I am overheating at just getting around, I cant drive two miles here in Seattle, read that cool, and it will overheat.

A little history, engine was rebuilt completely a few years ago, block was tanked and cleaned, head rebuilt and all. I had the original radiator checked and it was toast so I bought one off of CL for a later model Dart.

The problem I found though is that the core is biased towards the engine compartment while the original was biased away from the compartment, end result, the radiator is too close to the fan so I removed the stock fan and am using a 16" electric fan in front of the radiator pushing air through. Ive had it there since 2017.

Ive lost coolant so replaced with only water and it overheated, last fall I did 50/50 new antifreeze, lost it this week.

The electric fan is here:
https://www.amazon.com/gp/product/B00VVWTAA2/?tag=fabo03-20

Upgr8 Universal High Performance 12V Slim Electric Cooling Radiator Fan With Fan Mounting Kit (16 Inch, Black) Comes with mount brackets , and tie straps kit
Maximum Fan CFM=3000 CFM, Maximum Fan RPM=2250 RPM
Size: 16 Inch, Thickness: 3.25 Inch
10 Blades, 12 Volts, 120W
OE Fitment or Replacement, Push or Pull Type

The radiator has a place for a sensor so I installed a thermostatic switch at 185︒F to turn on the fan. There is no fan shroud now nor never as far as I know.

I installed relays for all electronics per FABO and SSO suggestions. The fan circuit has a relay.

Since the radiator change the heating cooling has been topsy. I have put a new radiator cap on it, I have tried different thermostats at different temps, 160-185 I believe it is. I have an electronic temperature gauge inside the passenger compartment so I can see what the temp is and it certainly goes to overheating, 225︒F+, and only on a short two mile ride here is Seattle air temp was 60︒F.

I tried to run it while it was cooler here and it overheated so I drained antifreeze and removed the thermostat. It still overheated. Im pretty much at my wits end here and Ive been reading many of the posts here for overheating, Ive tried to make sure Ive covered all the suggestions so I guess my question is would the radiator the problem and should I just replace the damn thing with an aluminum 2 row? I wanted to try to get the original fixed so it would be the correct one but here in my area north of Seattle there is mostly no radiator shops. The man who did my previous radiator work died, I recently found out, a couple of years ago. Was going to take the car there to be fixed, I'm at that point.

Afraid to drive ANYWHERE!

Anyway, glad to be back online and want to get this fixed so I can drive her and I'm at the point of just selling her because of this dang overheating.

Any thoughts, new cuss words and such would be appreciated.

Thanks yall.