What size engine for the online/Youtube EC?

Stock head?

Well, I’m not going to impress anybody on this or any build I do.
True, there are people on here smarter and better at this for sure. But! This should be something that;

1: Not trying to impress anybody on.
2: Show what ya got and never be embarrassed by.
3: Perhaps learn something from
4: Enjoy the camaraderie of the board in some fun.

If you were going to an engine for yourself, because you’re in need of one and you’re going to do it anyway, why not just throw it in the mix? Stock headed or not. Perhaps showing how to do something heap as dirt isn’t really such a bad idea?

I think, IMO, that someone out there would and very well could benefit and even perhaps copy your build.

Here’s an example for anyone:

5.9 core then add in a
Spring swap that matches the new cam
Headers, intake and carb
Distributor and a curve kit

Power divided by CID is the formula
Then there is price to consider
Power divided by dollar spent.

I grew up and married early and children came quick. This leaves little to spend on anything else never mind a hot rod and its parts. Most of my youth until my late 30’s early 40’s was trying to the best I could with stock J heads. You can only go so fast with stock J heads in a 3700 lbs car and with limited funds and knowledge, you do the best you can with what ya got.

Perhaps someone is willing to take on the challenge with that in mind? IDK!
Will help someone out? IDK!
But it is another interesting take and route.

I wouldn’t build an engine just to compete.
I like your approach to the whole thing. And if I were building an engine for myself currently that fit the bill of the challenge I would absofreqkinlutely enter. If for no other reason then the camaraderie and maybe, even if ever so slightly help someone else learn. My biggest hurdle is not having parts that fit the rules and not currently needing an engine built for myself that would follow the rules. I can’t feasibly throw 2-4K at an engine just to enter. Even though I’d like to. I have a completely machined 72 360 and complete bottom end I could put together but I’d have to source a set of heads that would serve me no other purpose than this challenge.