I used to buy the "332" Modines for my '70 Monaco 383. Great longevity and better than many recores I've seen. 332 is for the '70-style square-corner tanks. The '66s had the round tanks, but the same core dimensions.
The price differentials are extreme, depending upon where you get the radiators from. The Modines I used to get were about $250.00, in the later '70s and earlier '80s. No need for a fancy aluminum item as the factory style radiators worked just fine in those cars.
There's a thread on putting a 5.7L Gen III Hemi in a '68 Plymouth. A neat way to put the modern radiator in that car. Fit just right, when done, too. Some radiator hose adaptations were needed, though.
Don't spend more than you have to . . .. period. Shop around. Even see if a local auto supply can get you one for about the same price.
CBODY67