original radiator core value

As to the title of your post...

Core value...

If the top and bottom tanks and the rad supports are good. (The actual rad core is less valuable.)

The tanks and supports I would pay around 75 to 125 depending on condition and if the proper tags are on it.

As for an entire rad that is in good shape and original 150 to 250.

On the earlier rads up through 67, 68 maybe 69 there was a removable tag soldered to the top tank, that is the rad part number. It determined if it was standard cooling, AC or HD cooling rad core.

If the rad had been re-cored in its life the tag is meaningless, but to a purest restorer it is worth a few dollars

I have 3 67 small block radiators

1 has been re-cored and the part number tag is missing ( original rad to the car)

1 was OEM, had the tag and is the HD cooling version

1 has the tag but was recorded with a 3 row so the tag is just for show.