Radiator..??

Copper / brass and as OEM in style as possible

If an option exists, go for HD cooling / AC option.

22x17 is stock. VERY late years might have had a 26x17 but don't quote me on that.

The BB rads had larger inlets and outlets and MIGHT have been 3 core.
(Someone can confirm that)

383 GTS and Formula S had 22x17 and cool just fine.