K Frame
You have something unusual. It might be a LATE 1972 V8 A body unit.
This is from the Schumacher site pictures.
The one above is a 68-72 V8 A body K member according to the Schumacher site. Note the 3 holes in the middle of the flat section.
Yours have those same holes.
Now here is a B and E body K member. ONE hole:
A frontal view would help since the B and E K members that I have seen are curved across the front while the 67-76 A body units are flat.
Same goes with the lower control arms.
The A is flat across the front, the B and E are curved.
B body: