Intake and exhaust manifold

[Swedchevy67]

Hi!
Just got me a 69 C10 with original 6 inline. My plan is to keep it
that way. One of the issues is the intake and exhaust manifold, it’s
not in good shape. Are those parts still on the market (original) or
is there any compatible parts that’s better to look for?
I might consider to replace the Rochester carb for a 2 barrel Holley.

['68OrangeSunshine]

There are high performance parts for the Chevy L6s. Check out the following:
www.inlinersinternational.org
www.12Bolt.com
www.cliffordperformance.com
Good luck.

[RustyBucket]

Are yours leaking? Pitted cast iron manifolds can be pretty cruddy & ugly and still be functional. They are thick castings. If they're leaking at the gaskets you can dress up the flanges & install new gaskets. Be VERY careful not to wring off bolts & studs disassembling old rusty(like yours) manifolds. Penetrating oil, maybe a little torch heat & tapping them sharply with a hammer helps break 'em loose. If yours are not salvageable check for used parts on this site's classified section. They rust & crack sometimes but they don't wear out. I hate to think how many 6cyl. iron manifolds have gone to scrap......
.... OR there's the hi-perf. after market items like 68OrangeSunshine suggested.

[sick472]

I am seeing some pitting in your photos. Is that all that you are refering to when you say they are not in good shape? Cracks and warps are what make manifolds "not good".

I would not hesitate to sand blast those and reuse after removing and inspecting those areas for good thickness and checking the mating surfacces for flatness.

If you are concerned about the appearance alone...get some new ones if available.

[jabborabbo]

When I replaced the manifold gasket on my ‘67 a few years ago (the manifold had never been off the truck - it has a good bit or rust on it too), I sprayed the bolts and nuts down with Aerokroil two or three times a day for three days...and didn’t break anything! I’ve heard that removing a bolt that breaks inside the hole is a real PITA....

[Swedchevy67]

Originally Posted by jabborabbo

When I replaced the manifold gasket on my ‘67 a few years ago (the manifold had never been off the truck - it has a good bit or rust on it too), I sprayed the bolts and nuts down with Aerokroil two or three times a day for three days...and didn’t break anything! I’ve heard that removing a bolt that breaks inside the hole is a real PITA....

Great 👍

[Swedchevy67]

Originally Posted by sick472

I am seeing some pitting in your photos. Is that all that you are refering to when you say they are not in good shape? Cracks and warps are what make manifolds "not good".

I would not hesitate to sand blast those and reuse after removing and inspecting those areas for good thickness and checking the mating surfacces for flatness.

If you are concerned about the appearance alone...get some new ones if available.

Good idea. I try that 👍

[Swedchevy67]

Originally Posted by Swedchevy67

Hi!
Just got me a 69 C10 with original 6 inline. My plan is to keep it
that way. One of the issues is the intake and exhaust manifold, it’s
not in good shape. Are those parts still on the market (original) or
is there any compatible parts that’s better to look for?
I might consider to replace the Rochester carb for a 2 barrel Holley.

The heat exchanger on the exhaust manifold is hanging loose, and the
spring doesn’t have any purpose

[RichardJ]

Is the end of the EX manifold broken?

There should not be a bolt in the end holes of the manifold. There should be only a short locator stud in end holes in the head at both ends. The locator studs are threaded into the head and can be replaced with longer threaded studs when using aftermarket thin tube headers, but not with stock cast manifolds.
The 3rd hole in, from both ends of the head were originally 1 7/8" threaded studs with nut.
Picture is borrowed from this forum.

[Swedchevy67]

Ok. I will take a deeper look at it 👍

[sick472]

Richard...you've got good eyes!