I need some help identifying this engine, it is a little deal between me and a friend of mine. He says you should be able to identify it from the ports alone, and will not tell me. I'm out and out stumped. He also says it is one of the "holy grail" motors (if it helps at all, it's not a boss 429. I tried to guess that already haha) thanks for any help in advance!!

https://i.imgur.com/hxFrGA4.jpg