Correct Radiator #?
Here's how you find out any part number.
Go to mymopar and download the 1970 Parts Book.
In the parts book, go to the illustration section of the parts group, in this case Cooling.
Find the reference number and name of the part we're looking for.
In this case it looks like they are calling the whole radiator 'Core' 7-11-3
Now we go to the text page to find the part number for our specific model and options
V,L = Valiant, Dart
The part number was 2998 945 with A/C or 2998 974 without A/C.