Looking to find radiator cap for 1974 Cutlass Supreme 350 Rocket

 

rc33 is on my supreme..for whatever reason,there's rc27 on the salon..both are 15lb closed system i believe..

 

Check your local auto parts store, or their online store if you don't wanna actually go to the store.

 

72Vert, I agree with you. If you radiator has an overflow, the radiator cap would with the double seal makes sense so the overflow goes down the tube. Wonder if the original radiator did not have this option and that is why the original caps did not have the double seal. But wondering why your cap is overflowing if not overheating