Thanks guys...Is there an easy way to check and make sure that there
are no leaks in the salvaged radiator?

a) Bring a cap/plug to screw into one side of the radiator.
b) Bring an air tank connected to a shutoff valve connected to a
pressure valve to screw into the other side of the radiator.
c) Open the valve to pressurize the radiator (don't overpressurize).
d) Close the valve and use the pressure guage to see if the radiator
holds.

You can also put the radiator in a pool and pressurize it and look for
bubbles. Heavy to handle though.

You can also fill it with water and then pressurize it and look for leaks.