Skip and High Test, Your thinking is good.
High test, while your answer is good. The 53 and 54 both had the 235 6-cyl. The engine I'm thinking of is from a different decade, and was offered for only one year in the Vette.
But, went on to be one of the "staple" high performance engines for Chevy. It was offered in 2 different decades.
But I was thinking "production" engines. The ZL-1 was more of a specialty motor. And was way rarer than the motor I'm thinking of. And the Wankel, while cool, never made it into a production Vette.
Hint:If you start thinking of cars after the "Mako" years, you're wrong.