well you have a, forgive me, bastard size rad. (if you have a 68-71 J2000)
the buick rads where the second in the size line, 327 being the first and the AMC line being the last.
since i had the smallest with my OE 327, i opted to swapp out the rad support to that of a 77 wag.
that way i can use AMC rads, which are ezr to get at a pic n pull in NM than a fancy AL one in NE.
i have a store bought 4 core and run cool in town..but then i have SBC.
but no matter what rad you get, get a good shroud and (IMHO, a thermo clutch fan)
in the pic, OE rad support front, '77, rear.
no location of left hand support.
"Kelly, a tiger has only one weak point, and that's it's ass. You gotta hit it point blank and you gotta hit it from behind!"