I'm having a major problem with determining where the vacuum lines coming out of the firewall on my friends 1988 Camaro Vin E 305 engine. I have included the two pictures to try and get help.

The longer lines appear to be going into the firewall to the heater control head and on it there are going to the grey and purple and the two shorter lines go into the firewall but I cannot determine where they are connected in there.


I need help knowing what each get connected to on the engine. I would like to say thanks for you help ahead of time.

 

The grey is the vacuum "supply" to the control head; purple goes from the control head to the heater control valve.

The grey should pick up its vacuum downstream of the check valve (which I think should be where that white plastic union is but I'm not sure), and the Orb Of Power should be on that same line.