Hi, new to forum

I need some help identifying an Isuzu engine. I purchased this engine new online. It was sold as a 4JJ1 and by all appearances, it is that. My problem is it has no ID tags and when I go to purchase parts??? I have the original paper sales tag that was attached to the engine that gives (?) part number. I have contacted Isuzu and given them all these numbers but haven't heard from them. Is there a way I can reverse ID this engine by casting numbers,accessory numbers-starter alternator or part numbers on wire harness. Somehow I'm going to need an ID tag with proper serial number and engine number. Is this possible?
Any help will be greatly appreciated!!!!!!!!!

Thanks,

Jim