I have no clue where these go or where they connect. I rewired the other vacuum hoses in the right spot but I'm stuck with these last two.

 

 

Sent from my iPad using Classic Zcar Club mobile

This is on your 1976 280Z correct?  Does the car have factory AC?  The hose going into the Firewall controls is the main vacuum source for the Vacuum operated heater controls.  A lovely Rudi Goldberg collection of Vacuum selector valve and Vacuum pots that makes all the Climate controls work.  Have a good long look at the FSM, It's available online. 

The white Plastic Tee is not stock and has been added by someone.

 Take some pictures of heater control panel and levers and also up by the passenger side strut. There should be an Vaccuum accumulator tank there and one ( or Two ) elctro Vacuum switches. Setup varies oif car originally came equipped with AC.