Vacuum hose help needed
 

I need someone with more experience than I on all the vacuum lines I need to run on my 1984 c10. I need to know where there needs to be one and where they run to. I would narrow it down but I am not sure I could. Any help would be greatly appreciated. Thanks in advance.

Re: Vacuum hose help needed
 

Need to add just a bit more information if you want a decently detailed answer.
What engine do you have?
What Transmission do you have?
Federal, California, or the High Altitude version of Federal or Cali emissions?

Autozone.com has most of the 1984 vacuum diagrams for the smallblock and Inline 6 engines.
On that site;
There are Nineteen different vacuum diagrams for the 1984 4.1L 250CI I6.
and
There are Thirteen different vacuum diagrams for the 1984 5.0L 305CI V8.
and
The Stock C10 only came with a 305 in 1984. Even so... there are Six different vacuum diagrams for the 1984 5.7L 350CI V8 even tho they only came in the 20 & 30 series trucks.

If you have stripped off your emissions...
You still need ignition vacuum advance, PCV vacuum and breather, and vapor canister purge teed into the PCV line along with the ported vacuum control line (so you don''t stink up the barn or garage with the aroma of raw fuel).

PCV and canister purge should use SAE J30R7 rated Fuel and Emissions Vapor hose.

Re: Vacuum hose help needed
 

I am sorry I guess I should've given that info. I have a 350 crate motor that I've put in mine. No emissions from CA. I have a break vacuum that I have no idea where it goes. I have two vacuum hoses that look like they come off wires that go to the transmission. I have been told they are the converter locker wires. I just don't know where they go as far as the vacuum lines go.

Re: Vacuum hose help needed
 

Do you mean the vacuum break for the choke on your Rochester Quadrajet or Rochester 2G?
Or...
Did you mean the brake booster vacuum? Brake booster vacuum is raw manifold vacuum. Should be a port in one of the intake runners behind the carburetor.

Transmission is a TH350C or TH700R4?
Both have TCC control wires that plug in just above the pan rail on the LH sde of the tranny.

Re: Vacuum hose help needed
 

The crate motor came with a holly carb. The transmission is a th350 c. I meant the brake booster vacuum.

Re: Vacuum hose help needed
 

Very interesting. I'm going to do this and see if it helps with the smell of gas on my non emission 350 topped with a 77 model q-jet (no 45 degree provision for vapor canister tube like the later models have) that I have in my 86.

Re: Vacuum hose help needed
 

Basic Evap or Charcoal can hookup. This is how GM did it on the cars and trucks in the 60's and early 70's.
If the carb has a bowl vent inside the air cleaner you don't need the bowl vent line. Cap off any connections on the can which had hoses that you are not using.
If you want it clean and neat run steel brake line with no threaded ferrules along the firewall and inner fender rather than draping the lines from the engine to the evap can. You can run rubber along the valve covers to the firewall and from the inner fender to the charcoal evap can.
Attachment 1520729

Your Holley will have "ported" and "manifold" vacuum taps. Usually the ported vacuum is above the throttle plates and the manifold vacuum is right at the manifold level at the bottom of the carb. If you post the model number I can probably find a diagram of which taps are what type or you can google it. Holley likely has recommendations of what taps to use for what purposes.

Following the above diagram;
Vacuum ignition advance is hooked to the same ported vacuum as the evap can purge valve vacuum.

The TH350C also has a Vacuum Modulator on the RH side of the transmission. It'll need to be hooked up to a ported vacuum tap. I usually run steel brake line down from the engine to the transmission tail and then use short sections of vacuum line at the ends.

The TH350C has a Kickdown Cable. You'll need a Holley Bracket for this cable that fits your carb and intake.

Brake booster vacuum line is direct to the rear of the manifold.
PCV and Evap can vapor purge are direct manifold vacuum on the front of the manifold or the base of the carb.