New Ride! 78 GMC. *The build thread that never was?*

[Chief Brody]

Does this carb look right? I have never seen one with the little spring thing going from the accelerator pump arm to what I'm guess is a power valve.

I don't think my quadrajet has that

 

[kennyw]

Looks like a quadrajet I had on a 1979 K10. I don't see anything strange.

 

[y5mgisi]

Even the little spring thing off the accelerator pump arm? I have never seen that before.

 

[Babaganoosh]

Never seen that before, might be worth it to toss a rebuild kit at it and see what's going on!

 

[76zimmer]

I've never seen a quad with that bend rod/spring on the acc. pump arm either. Someones cobble job?

 

[y5mgisi]

I don't think so? It looks oem.

 

[y5mgisi]

Still havent figured out for sure what that thing does, but it does apear to be an OE late 60's 396 quadrajet.

 

[skunked]

those were OE on 400's IIRC, late 60's. Pull the numbers off the carb and you'll know for sure.

 

[y5mgisi]

So aperently it's a idle vent valve. Supposed to allow the fuel bowl to vent externally during idle.

Also it's a 67-69 application.

 

[campfire]

So aperently it's a idle vent valve. Supposed to allow the fuel bowl to vent externally during idle.

Also it's a 67-69 application.

So...your engine has definitely been messed with, then?

 

[y5mgisi]

The truck originally had a 350. The story is that the previous, previous owner had a local shop swap in the supposedly rebuilt 396 and rebuilt the th400.

So i created a new thread for the crew cab. All updates shall take place over there from now on. Here is the thread,

http://coloradok5.com/forums/showthread.php?p=3531814#post3531814

 

[82355]

So...your engine has definitely been messed with, then?

GM never installed a 396 into a 1973-1987(1991) truck, so it is probably original to the engine.

Martin