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**N2TRUX** · 09-06-2003, 09:34 PM

Ok, trivia time. I'm detailing the 77 today, and ran acros a couple of things I need answers to.

I have a line running out of the back of the carb base plate that is blocked off. I can't find any place that is went to. Does this come capped off from the factory? I know this isn't the way the factory would do it. Maybe someone last the cap, and used this instead....

**N2TRUX** · 09-06-2003, 09:34 PM

Another view...

phantom dually · 09-06-2003, 09:49 PM

How about a vacuum line for the heat/ac. Alot of trucks used it to open the vacuum canister for vents to sitch from dash to floor etc etc.

*mike reeh* · 09-06-2003, 10:08 PM

thats probably not the stock carb. none of my 77s or any quadrajets of mine for that matter, have ever had that hookup. its null & void in your application

mike

**swervin ervin** · 09-06-2003, 10:16 PM

I think this is the port for the air cleaner. Can't remember for sure. But I believe this hose went to the hot air sensor inside the air cleaner.

If you don't need it, buy a cap to go on it. It will look better than a piece of hose stuck on it. As Mike said, it may be you have a newer Q-jet on there too.

**N2TRUX** · 09-06-2003, 10:42 PM

Quote:

Originally posted by swervin ervin
I think this is the port for the air cleaner. Can't remember for sure. But I believe this hose went to the hot air sensor inside the air cleaner.

Nope, it's not that. The hot air sensor is hooked up to another line.

I think mike reeh may be right. Since everything appears to be hooked up and working correctly, I am going to assume it's not supposed to go anywhere. Tomorrow when I go by the auto parts for hose clamps, and plug wire clips, I'll get a vacuum cap too...

*mike reeh* · 09-06-2003, 11:07 PM

if you give me the exact specs of your truck (year, engine, state, tonnage, AC, etc) Ill scan in the GM vacuum diagram from the 77 manual..

mike

**swervin ervin** · 09-06-2003, 11:20 PM

After looking at the pic again, I think this port was used for the EGR bleed solenoid on my 85. You don't have a EGR, right? So I say the carb has been swapped out to a later model. Maybe. Could be. Heck I don't know. Cap it with a vacuum cap.

**N2TRUX** · 09-06-2003, 11:21 PM

That would be cool Mike. It's a 77 Cheyenne with a/c and 350/350 auto. It's a 2wd, 1/2 ton, and it's not a Cali spec truck. What else ya need?

*mike reeh* · 09-07-2003, 12:39 AM

interesting. all the california emissions trucks didnt have that connector but apparently your truck may have needed it:

thats for light duty emissions which I would assume your half ton is.. Here is the heavy duty emissions..

hope this helps

MylilBowTie · 09-07-2003, 03:11 AM

Maybe a rear vacuum brake? Looks like it was taken off.

Canadian-Ron · 09-07-2003, 10:37 AM

cap it and forget it

09-06-2003, 09:34 PM	#1
N2TRUX Happy to be here Join Date: Mar 2000 Location: Cypress, TX Posts: 39,021	Where's this go? Ok, trivia time. I'm detailing the 77 today, and ran acros a couple of things I need answers to. I have a line running out of the back of the carb base plate that is blocked off. I can't find any place that is went to. Does this come capped off from the factory? I know this isn't the way the factory would do it. Maybe someone last the cap, and used this instead.... Attached Images __________________ Follow me on Facebook and Instagram @N2trux.com Articles- "Jake" the 84 to 74 crewcab "Elwood" the77_Remix 85 GMC Sierra "Scarlett" "Refining Sierra"

09-06-2003, 09:34 PM	#2
N2TRUX Happy to be here Join Date: Mar 2000 Location: Cypress, TX Posts: 39,021	Another view... Attached Images

09-06-2003, 09:49 PM	#3
phantom dually Project92 SWB stepside Join Date: Feb 2003 Location: Louisville KY Posts: 4,792	How about a vacuum line for the heat/ac. Alot of trucks used it to open the vacuum canister for vents to sitch from dash to floor etc etc. __________________ 92 C1500 stepside 496 Stroker Competiton Engineering Ladder bars/QA1 coilovers. Dana 60 rear with 4.10 gear and posi. Bonspeed Palisade 20x12 in rear w/335/30/20 and 20x8.5 front w/245/40/20. 5/8 drop with Belltech springs/DJM spindles/drop shocks. WWS Progress thread http://67-72chevytrucks.com/vboard/s...d.php?t=140448

09-06-2003, 10:16 PM	#5
swervin ervin You get what you pay for Join Date: Dec 1999 Location: Cherryville, NC Posts: 4,798	I think this is the port for the air cleaner. Can't remember for sure. But I believe this hose went to the hot air sensor inside the air cleaner. If you don't need it, buy a cap to go on it. It will look better than a piece of hose stuck on it. As Mike said, it may be you have a newer Q-jet on there too. __________________ Mike 1985 Chevy C-10

09-07-2003, 03:11 AM	#11
MylilBowTie Right turn Clyde Join Date: Nov 2002 Location: Cincinnati, Ohio Posts: 2,911	Maybe a rear vacuum brake? Looks like it was taken off. __________________ 1974 C25 LWB: 454 4bbl Carb / TH400 / 3.73 1992 Camaro RS 305 TBI

09-06-2003, 10:08 PM	#4
mike reeh 5 day ban, learn to behave. Join Date: Nov 2002 Location: san diego, ca Posts: 683	thats probably not the stock carb. none of my 77s or any quadrajets of mine for that matter, have ever had that hookup. its null & void in your application mike

09-06-2003, 11:07 PM	#7
mike reeh 5 day ban, learn to behave. Join Date: Nov 2002 Location: san diego, ca Posts: 683	if you give me the exact specs of your truck (year, engine, state, tonnage, AC, etc) Ill scan in the GM vacuum diagram from the 77 manual.. mike

09-06-2003, 11:20 PM	#8
swervin ervin You get what you pay for Join Date: Dec 1999 Location: Cherryville, NC Posts: 4,798	After looking at the pic again, I think this port was used for the EGR bleed solenoid on my 85. You don't have a EGR, right? So I say the carb has been swapped out to a later model. Maybe. Could be. Heck I don't know. Cap it with a vacuum cap.

09-06-2003, 11:21 PM	#9
N2TRUX Happy to be here Join Date: Mar 2000 Location: Cypress, TX Posts: 39,021	That would be cool Mike. It's a 77 Cheyenne with a/c and 350/350 auto. It's a 2wd, 1/2 ton, and it's not a Cali spec truck. What else ya need?

09-07-2003, 12:39 AM	#10
mike reeh 5 day ban, learn to behave. Join Date: Nov 2002 Location: san diego, ca Posts: 683	interesting. all the california emissions trucks didnt have that connector but apparently your truck may have needed it: thats for light duty emissions which I would assume your half ton is.. Here is the heavy duty emissions.. hope this helps

09-07-2003, 10:37 AM	#12
Canadian-Ron Registered User Join Date: Sep 2003 Location: canada Posts: 43	cap it and forget it __________________ my project........... my hell......... http://members.shaw.ca/ronmccoy/



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