No.
Use your regular cap on the stock radiator.
A cap with a spring that seats on the inside shoulder of the filler neck is sufficient as long as it has a poppet valve that opens to allow coolant to flow in and out of the overflow tube.
As long as coolant can reach the overflow port, it will work. Be sure to fill your radiator to the top of the filler neck rather than leaving an air space in the upper rad tank.
