i am changing my engine and i am not sure where my dash vents get vacume from i have 2 vacume lines coming throught the firewall, right besisde the heater box above the tranny, through a rubber boot with other wires. one is long and one is shoter. i think the longer on controlled the heater diriveter valve or how ever you spell that. is the shoter one where i get the vacume from? it is an 89 RS 305

 

Right; hook that one (should be purple, the other one should be white) up to any place on the intake or plenum or whatever you have, that has vacuum full-time.

The factory used a check valve and a vacuum reservoir to store vacuum so all your little doors would sty put when you floor it. It'd be a good idea to locate all that and hook it back up properly as well, so your heat system doesn't fall back to defrost and then back to wherever you have it set, every time you accelerate.

 

thanks. both of my lines are black the come out of the fire wall. i removed that vacume ball. i new it was to store vacume but i didnt realize why haha... oops. maybe ill install that agian if it becomes a pain.