What size engine for the online/Youtube EC?

Depending on the rules, you could do a two step challenge. For example:

Step 1 360
Step 2 same 360 stroked to 408 (perhaps some head/cam mods to account for the increased displacement.
Maybe if this gets off the ground--then yes more varied entries would make sense, but not this time, I wanna keep this simple and straight forward. J.Rob