83 C10 Vacuum System [HELP]

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Bo69

Junior Member
Joined
Aug 29, 2023
Posts
17
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Location
KC, MO
First Name
Bodi
Truck Year
1983
Truck Model
C10
Engine Size
305
Now I have a comment for all the I'm just going to L.S. swap it people. This isnt just aimed at you. If you have a rough time trying to sort out a stone stock sbc. Imagine how your going to feel trying to adapt an engine into a vehicle it wasn't designed for,Integrating modern EFI and Engine management. I can't say that I think doing an ls swap is the right first swap for someone unless they are very mechanically inclined.
I agree 100% which is why I planned to take it to a professional rather than attempt it myself.
 

Bo69

Junior Member
Joined
Aug 29, 2023
Posts
17
Reaction score
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Location
KC, MO
First Name
Bodi
Truck Year
1983
Truck Model
C10
Engine Size
305
Bo69, what engine type were you thinking to swap out to?
The vacuum lines are complicated but not impossible to sort out. Most can be removed and blocked/plugged at the carburetor.
The Quadrajet is a fine carburetor easy to rebuild and can provide outstanding performance.
Your truck may be later than my 85 but much of the vacuum plumbing looks the same. I can help you sort through it if you wish. Keep in mind I am NOT an expert.
Thank you for offering the help, I ended up capping some of the areas off and just routing it all the best I could with what was still left on the truck. Did I do it all technically correct, probably not but this truck ran for years leaking oil sometimes running it when it was bone dry, random types of oils got thrown in it (whatever was sitting around) & it had a cracked radiator that was also bone dry so it had to of been constantly over heating. This was before I took ownership of the truck. Also like I said I plan to swap motors so I’m honestly not to concerned with what happens to this motor anymore. I plan to swap to a 5.3 LS motor eventually just for more power and to modernize the truck mechanically. For now the current old 305 motor is running perfectly fine, it fires right up even when we have had below 0 temps this winter, the oil pressure stays good, I checked the vacuum with a gauge it is also good. I’m sure if I wanted to keep this motor it could last forever.
 
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Laqota

Junior Member
Joined
Apr 16, 2024
Posts
17
Reaction score
10
Location
Joplin
First Name
Jerame
Truck Year
1983
Truck Model
C10
Engine Size
305
Hey man. Don't really worry about vacuum on c10's. I can see by your profile that you live in Kansas City, which doesn't have heat/smog emission laws. So almost all of that you can pretty much delete.

The things that are important to have vacuum is your Vacuum Advance (IMG_5428 Vacuum on Distributor), Your choke pulloff (IMG_5428 Vacuum on Carb), and your cruise control (IMG_5432, the drum that has an arm that connects to the carb throttle). And the heater/AC Vacuum. You don't have to connect anything to your Canister cause those things, especially if it's old, get leaky.

Things you can plug is the EFE, and Manifold ports that aren't being used. There is also vacuum that comes from the back of the carb, but not on the carb In front of the distributor that connects to the intake manifold and is usually what people connect the brake booster and cruise control to. This is manifold vacuum and works exactly like the carburetor manifold vacuum does, it's just in a cleaner spot and gets it from the Intake directly.

The valves on your Thermostat (EFE TVS) and on your intake (EGR TVS) shouldn't be plugged unless you are leading them to sensors n stuff. If your aren't leading them, just leave them blowing. These aren't really necessary to connect but if you want to do it, it never hurts. EFE TVS releases heat from coolant, and EGR TVS releases heat from engine. EFE TVS should be hooked up to your temperature sensor and manifold vacuum through another hole. It should also be hooked up to your EFE. EGR TVS should be connected to your EGR bleed and Manifold vacuum through another hole. Then other holes on them should be plugged.
 

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