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73-87 Chevy _ GMC Trucks => 4 Wheel Drives => Topic started by: tigwelder on February 21, 2011, 07:25:38 pm

Title: 85 K20 exhaust manifold.
Post by: tigwelder on February 21, 2011, 07:25:38 pm
1985 K20.did GM use exhaust manifold that looks similar to a header?left side looks like cast iron then toward the #5 plug it turns round like a header tube and has heat riser where pipe bolts to it.
Title: Re: 85 K20 exhaust manifold.
Post by: tigwelder on February 21, 2011, 08:36:02 pm
just had another look and appears to be some kind of headers.looks factory. exhaust pipes have a shield from flange to muffler.
Title: Re: 85 K20 exhaust manifold.
Post by: Psycho71 on February 21, 2011, 08:37:14 pm
Mine were tube style manifolds on my '85 K20 burb. The were tapped at the ports for smog equipment. Needless to say, they WERE. Now there are real headers where those pieces of junk were. I was shocked when I took them off to see how much of the exhaust port was blocked by those taps. I don't know how they flowed anything, much less what the engine needed to.
Title: Re: 85 K20 exhaust manifold.
Post by: tigwelder on February 21, 2011, 08:49:08 pm
sounds like what i got.
Title: Re: 85 K20 exhaust manifold.
Post by: Psycho71 on February 21, 2011, 08:51:25 pm
I seriously considered just pulling and plugging all of the smog tubes on mine. But they weren't gonna come out without a an epic battle. So headers were the way I went.
Title: Re: 85 K20 exhaust manifold.
Post by: tigwelder on February 22, 2011, 07:05:18 am
the heads were just replaced on the truck i bought and the guy had the manifolds plugged.
Title: Re: 85 K20 exhaust manifold.
Post by: Psycho71 on February 22, 2011, 07:55:19 am
Hmm, I'd take one loose and see if he got the whole assembly out. If so, I'd personally leav'em on there. If not, you'll see how restrictive how that assembly could be. They probably aren't as good as headers, but couldn't be too bad on a mild to stock motor.
Title: Re: 85 K20 exhaust manifold.
Post by: tigwelder on February 22, 2011, 05:10:00 pm
does the heat riser go on left manifold?this truck has it on drivers side with springs on studs.leaks on both sides.can i use regular studs so i can tighten the pipes to get rid of the leaks?