Can someone tell me where this coolant line goes to? I am finishing up my rebuild and can't remember where it went.

goes to your throttle body, i loop it back into the other one that is the return from you throttle body, and just bypass the coolant going from there, or you can cap it, i capped my iacv ones also,and when my new turbo lines get here i am going to do some more rerouting of coolant lines

I wouldn't recommend capping the line. One of my caps busted and a lot of coolant leaked out of the motor while I was driving. She started overheating. I would just bypass the throttle body as idahotuner suggests. Coolant circulates arount the throttle body to keep the throttle from sticking/icing over during the colder months. It will also warm up the air going into the motor. Just run that coolant line from the nipple you have circled to the nipple that portrudes next to the factory water temperature sensor. I hope you understand what I'm suggesting. Let us know if you don't.