According to A.J. Moore, competition director of Lake Erie Speedway, crate racing has been a success this year. Last year the track’s late model class was half “built” racing engines and the other half crates. Crate racing engines performed well enough that this year there were only 7 “built” engines out of 30 or so regular entries. Moore says that only one built engine won a race this year, too. In part, those numbers are attributed to racers who have sold their built engines to purchase a crate, but also because there are rules that contain the performance of a built engine so it is equal to the crate engines

but also because there are rules that contain the performance of a built engine so it is equal to the crate engines

ya, just do like Flamboro thunders do, make the builts run parts that can't possibly keep up, then the crates rule. (works especially well if one of the main sponsors is a crate supplier). you can tell all the builts, they are getting lapped every 10 laps

Well we ran a built there for our first year and we didn't get lapped until about 6 races in then we started to loose 2 valve guides cause the engine shop buggered my heads. Needless t osay the sponsor who sent my heads didn't pay, when the engine builder show up and I grabbed him by the throat he changed hi tune pretty quick when I told him was gunna eat the carbon build-up his monkeys left in the ports. I had stuck these "rebuildt" heads on my $4000 dollar Rudy Held short block. And you think I wanna play that game?

Double file restarts.  Leader chooses what line

Forcing built motors to run say, a 390 CFM carb spacer plate would choke them with current technology and all it would do is force yet another round of R&D by engine builders passing on those costs to the racer. It also has the potential to burn up the engine faster. This is because the racer / builder will have to learn a new fuel curve to get the engine to run to its potential and as mentioned, may require experimentation with camshaft profiles.

Hmm I'm not sure with over 50 years of the SBC being around any yocal is going to discover anything. And passing the smoke and mirrors on to the customer is what lead to the crate engine being so prominent.
You will never convince that built motors are the way to go and you are forgetting the biggest point of all. THEY FAIL AND DIE at an astronomical rate. Oh yah the engine builder will be bugging the hell out of you to "freshen it" every season or saying "you know you bring it back and we can get a few more ponies out of it". Too funny.
Lets be serious folks we need to add to the number of participants with an economically sound rules platform. Three or four fast cars with LM budgets will not do anything for the class.