With all due respect, you bought the wrong radiator for your truck in my humble opinion.
There is a better choice available on eBay which has the same tank design as the original Harrison brass radiator, If you paint it black, its hard to tell from the original. It fits perfectly and has the mounting holes already drilled. The last one I bought was $200.00 to my door.
If you search eBay for aluminum radiator for '47-'54 Chevrolet truck, you will see many sites with good pictures. Look for one that has the tank which looks just like the original radiator for these trucks.
