Were it mine, I'd try pulling the valve cover off and seeing if there is a head number, at least to check to ensure there isn't anything under there.
For what it's worth, the Nebraska test data says the engine in a 2-30 is an Isuzu 3AD1. But if the parts are suspect because of not having any tags on the tractor or engine, you may not be wise to go based on that number.
What parts do you need?