Somewhere between 1967 and 1971 the NHRA made radiators optional in supercharged applications. Keep in mind that NHRA was not the only game in town. There were many gasser groups and associations that had their own rules. Some even ran nitro!
If you look at some of the AA/GS cars you'll see that the "radiator" is actually a water tank with tubing connected to the engine block or cylinder heads. The supercharged cars did not have to idle or drive to the starting line, therefore water circulation was not necessary.
WF
This Ohio George car has a tank "radiator"
The Revell Kit seems to have no radiator or tank.
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Stone, Woods & Cook Has no cooling system. Match race trim?