22-inch Replacement Rad. for six cyl.?

I agree with RustyRatRod that a wider radiator will cool much better even with the 19" opening. The air isn't restricted to flowing in straight lines. My M.S. thesis in Mech Engineering was in heat transfer, but believe what you want. I have a Be Cool aluminum radiator with side tanks which I installed in my 1965 Chrysler. I considered installing it in my 1965 Dart 273. It barely fit between the frame rails but only if I cut off the overhanging lips on the rails, which I wasn't going to do. No, I didn't pay the $800 prices you see in the links since found it on ebay new for $50 I recall. It doesn't have side flanges but instead 4 tapped holes on the fwd side of the tanks, so I had to drill matching holes in my Chrysler radiator support. Using Evans Waterless Coolant since I want it to last (all my cars).

Re what radiators work in a slant, my 1964 Valiant had an unknown radiator when I bought it, so I'm running that until I find it is a problem. Definitely not Mopar A-body as it thin with a square top tank. It doesn't have the angled bottom outlet of a correct slant radiator, but the hose still fit OK. Copper, so likely no later than 1970's. Car came with a little Honda labelled battery and a M-B pusher fan in front of the radiator with no engine fan. Those are intended just to help the AC condenser (I have a 1980's M-B). Some gomer wired that fan directly to the key switch with no relay (yes, melted under-dash wires) and it didn't suffice. There is minimal room between water pump and radiator, which is why the slant recessed the water pump on the side of the block. I doubt you could fit a fan-clutch, even with the thinnest radiator you can find, and using a very thin fan-clutch (Jaguar or 1980's M-B). My 1969 Dart slant had factory AC and no fan-clutch as I recall. I couldn't fit one in my 1964 and had to use a thin nylon fan.