67 Dart cooling issues

Sledger46 - You're heading in the right direction by adding that 7 paddle fan ; good call !
A shroud is an absolute necessity on a street-operated vehicle , as it directs air through the radiator (pulls it through) .
Sealing is of paramount importance as well , otherwise the drawn-through air will simply chose the path-of-least-resistance (e.g. , it'll flow everywhere *except* where it's supposed to .
2.5" of clearance between the fan's blades / clutch face , and the rad core , is good ; best = fan sticking 1/4 to 1/2 way out of the shroud's opening .

A clutch --really , a de-clutching device-- will save on power and be more economical , as it declutches the fan at expressway speeds ; and as the operating temps climb , its spring / silicone cause the fan to turn faster than engine speed .

I'd recommend utilising G05 coolant with that aluminum rad (does your Dart's engine have aluminum heads as well ? I don't remember ...) , as it's a "Mixed Metals" coolant . It's the stuff that Ford and Chrysler use as factory-fill .
NAPA has their equal ("generic") brand of G05 , if you're so inclined .

Best of luck ! :burnout: