I have Googled this for awhile but can't find the answer.....I have a 59 Apache shortbed stepside, 235 engine. The original radiator is still on it but the core has disintegrated and I was going to replace the whole thing. Here are the specs:
Harrison
3135652
R-11A
58L

For the replacement, do I need to go with 2 or 3 core, or does it make a difference?

I found these on eBay:
Radiator 1

Radiator 2

Radiator 3

Thanks!