My car has had the Phoenix radiator for years, and years. About 5 or so years ago it started leaking at one of the tanks so I pulled it out to have a shop look at it. Hall did a good job on the Phoenix design. It is a combination of automotive, and heavy equipment radiators built as one.
My radiator needed recoring, this is where the heavy equipment part comes in. The core is from a fork truck. If you see one you will notice how tightly packed the fins are in those cores...and as others have said it is close to 5" thick.
While I had my radiator out I also replaced the pump, and thermostat. I used the Stewart piece and it is a very well built pump, using a shrouded impeller.
Stewart Water Pump.