[Mr70]

That IF is a Heavy Duty 4 core tank,shared by M/T & A/T.
That XP is a Heavy Duty A/T 4 core tank.
Together these make up the Big Block PD 4 core radiator used in 1970-72 Chevelles/Elcaminos.
If the passenger side tank has the 1st design "flat cap" tank,it's worth more then the later issued "slant cap" tank.