MonkeyWrenchRacing.com did a great explanation of Celica engine swaps. You're a bit sparse on details here, and I'm unclear if you're swapping a 2ZZ into a GT body, or you are swapping a 2zz JDM into a GTS body where it is an American car, but the engine is Japanese. So I'm going to assume you are also swapping the ECM from a JDM GTS to an American GTS ECM and not using the ECM that may have come with the JDM engine because of the immobilizer function. In the case of a GT body and 2ZZ swap then, yeah, the harness isn't going to be quite the same but according to MWR it's adaptable.
They stated the following: "Wiring – your stock 1ZZ engine wiring harness will work but you’ll need the MWR VVL connector kit to add the VVL connections." And of course the VVL connector kit is something they happen to sell there. But anyway here is the article to read for yourself. I hope that helps you out amigo. Good hunting.
MWR Article on Celica Engine Swaps [
monkeywrenchracing.com]
