what is ?

[305chevy c-10]

this may be a dumb question but .what is the ball looking thing under the hood on the driver side .i know it has a vac line to it .i just changed the intake and carb off my 305 and now hooking lines back up .i think i got it right . distr vac to timed vac on (600 holley)carb ,pvc port on carb to pvc  on driver valve cover ,trans vac and power brake vac on vac port on(edelbrock ) intake .now i just gotta figure how to set timing .was at home bored so i used some parts i had laying around

[305chevy c-10]

this?

[topp]

Vacuum canister.

[zieg85]

Vacuum canister.

For the AC controls inside the cab to operate the vents/defrost dampeners.

[305chevy c-10]

where does it need to be hooked to

[bowtieman82]

it hooks up on the card. there a small port that has vac. all the time.  on holley it on the passenger side on edelbroke its on the right front side. q jet u will have to use a vac. gauge to find it.  and that ball thing is for vac. controls on your heater/ac it helps to keep the vac. at a steady level so your controls work the same all the time. if u dont have it, when u are driving around sometime u will be able to change the setting and some time not.

[305chevy c-10]

ok thanks i will buy some more vac line and hook it up .u r talking about a full vac port right .its the small port thats comes capped when u buy a holley ?