I'm not advocating using or owning one, just that it exists. You need to know the displacement of the engine for accurate compression #.
So max allowed displacement is usually used when checking limited engines.
And I've "heard", ahem, a length of a wire tie sucked into the intake port lodged between the intake valve and seat before the rockers are removed will give whistler (and the tech inspector) fits.
On to the bore scope, they are paraded around too while checking limited/spec engines.
I recall a spec SUPR Brodix head engine being checked with a scope and the tech inspector saying "interesting..long pause...everything looks good here, button it back up". I won't get into all that was going on inside there, but the obvious externally was the angle mill, based on the deck thickness measurement holes drilled in the front of the heads, one had about 1/4" of material under it.... and the other was cut in half!
Engine rules in limited dirt tract racing are useless unless enforced correctly. The flood gates aren't open, their long gone.
The GM crate engine series like FASTRAK and RUSH/NE SMITH are better with track able seals and heavy fines, punishments for infractions inside the seals for re builders as well as owners and drivers.
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Captain, the head casting # and cubic inch/block casting will likely give you a decent guesstimate if it's likely stock components. Let me know if I can help.
HTH
