Krazy 300zx

Ok so here's my problem i won a 90' 2+2 300ZX that i bought off some guy. He said that the first engine messed up and he bought a jdm engine and put it in the car. The engine has a twin turbo emblem on the engine on the left side like the twin turbo engines do. But i am not too sure if it is one or just an emblem he bought and put on there. It does not have any turbos of course so is there any other way that you can find out if it is a twin turbo engine or just a non turbo. Any help would be appreciated thanks