A body radiators

Some things to keep in mind.

Is the new radiator the same thickness as the OEM rad.

If it is thicker will it fit ( shroud, fan etc)

Are the mounts in the same location, not pushing the core forward or backwards up or down.

Are the inlet and outlet on the correct side.

Are the inlet and outlet the correct diameter, bigblock radiators have larger dia.

Is the radiator sized correctly, fins per inch, tub I'd, tube spacing.