What size engine for the online/Youtube EC?

Go for it. I’m all for using cast iron IF you can tolerate porting that stuff.
I'm one of the few people stupid enough to do it, in certain situations. Got a set of W2s on the bench now, with one port done. A nice, quiet 305 cfm with a 2.02, but what sucks, is now there are 7 more intake ports and 8 exhaust ports to finish. Hes a close freind or the answer would have been "HELL NO"