What size engine for the online/Youtube EC?

I’m going to add that a build like this is probably the most fun I ever had building an engine. I sold my 1972 duster to a friend as a roller in the 1980’s. Needing an engine built I told home I would build him one. We started with the 1972 engine out of a Cuda (340) he had and honed the block, new rings and bearings, 484 purple shaft cam, a set of X or J heads I sold him that I knowing nothing cleaned up for him a little, and I’m not sure on what intake we used and a 750 Holley. His first trip to the track was his first ever and he ran a 12.40 something. He ended up in the 12.20’s that year and never raced again. I charged him 5.00 to build that engine and we bought a bag of jawbreakers to eat while building it. Great times.
Yeah, a little saddening to know that will never happen again. J.Rob