What goes here?

So I'm finally about ready to fire up my truck. However, I've had a few snags. I've been doing my work in an outdoor parking stall. Most engine components I've removed, I've just thrown in the back of my truck. Figured nobody else would have ause for them but me. I was wrong. As I'm putting things back together I'm realizing someone has stolen a few things. First off my camshaft pulley was missing. So was the coolant hose that goes from the thermostat to the back pipe. I got new pieces. The hose I got was from a carburated model. I just plugged the middle hole. I don't believe that is used in EFI models.
But, now I'm missing another hose. The one that goes from the throttle body. Is this a vacuum hose? Where does it go to. I cannot find any other connections I've missed. I've seen a couple pictures of peoples throttle bodies but the pictures do not show where the hose leads to.

well. it looks like coolant comes out of that fitting. ha! I assume back down to the hose I plugged.

I fired it up. The engine sounds great. But I guess my sanding job wasn't good enough. There is coolant very slowly seeping from the back corner driver side where the head meets the block. Things were looking good. Maybe I'll sell the truck.

Make sure you torque all the nuts and bolts to spec and you don't just have an "external" leak that appears it's from the head... After all that work I wouldn't sell it.

Those small hoses are for coolant to flow through the intake/throttle body the and "feed" temps to the ECU.

Yeah, I've definitely torqued everything to spec. I ran some of that powder stuff that is supposed to seal coolant leaks. So far so good. I'm gonna drive my truck to work tomorrow and break those pistons in good. I also have a better set of tires at work to put on this thing. I think I'm gonna keep this girl.