BB Radiator "I Think" ?

[hiperf69]

Ok, saw a thread a couple of weeks ago on here about Radiators and it prompted me to go look at one that I bought a year or so ago.
Trying to figure this thing out so, here is what I know,
It is a 4-core Auto 21'' core.
"iF" tank on driver side
"OA" on pass side with a"B" date
Has the original Tag that is only about 1-5/8" Sq.
Tag is coded "SK" and stamped 3008329
Any help would be appreciated ,
Thanks in advance ,Joe

[hiperf69]

Also noticed a small tag clipped on the lip of the tank with "AB" on it.
And the core and tanks look to be what I would call "Born With or together"
After looking at this, it looks like it has never had any tank Brkts. mounted to it.
Maybe it's a "BOP" Rad.
Anyway, thanks, Joe