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Old 11-27-2008, 01:24 PM   #1
5150
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Exhaust Manifold Bolt Sizes

I have some Ram Horn Exhaust manifolds that I dropped off to get coated and was wanting to coat the bolts too. What sizes are they??
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Old 11-27-2008, 03:04 PM   #2
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Re: Exhaust Manifold Bolt Sizes

9/16" x 2.1/2" outers
9/16" x 3" inners

I don't swear they are correct for all heads
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Old 11-27-2008, 03:11 PM   #3
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Re: Exhaust Manifold Bolt Sizes

Guess I should have said, sorry, they are stock 882 heads.
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Old 11-27-2008, 03:32 PM   #4
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Re: Exhaust Manifold Bolt Sizes

You'll need 8 thick washers for the outer 4 bolts, the inner doesn't use washers.
If you are going to use the locks then you should coat them too.
s/t
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Old 11-27-2008, 04:01 PM   #5
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Re: Exhaust Manifold Bolt Sizes

They should fit without any options/brackets bolted to them.
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Old 11-27-2008, 04:21 PM   #6
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Re: Exhaust Manifold Bolt Sizes

Lets's see'um after you get 'em back....now that my engine is out, and a friend gave me three sets of ram's horn manifolds (and two other set...Thanks, Mike), I'm thinking I might not want to reinstall the Hooker headers that came off of the engine.
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Old 11-27-2008, 04:24 PM   #7
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Re: Exhaust Manifold Bolt Sizes

No brackets, I'm running a serpentine setup
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Old 11-28-2008, 11:47 AM   #8
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Re: Exhaust Manifold Bolt Sizes

Got new ones for mine at Corvette America, not sure if all bolts are created equal when it comes to exhaust manifold bolts. Thought I read on here that they are special in some way

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Old 11-28-2008, 11:58 AM   #9
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Re: Exhaust Manifold Bolt Sizes

Quote:
Originally Posted by mbgmike View Post
9/16" x 2.1/2" outers
9/16" x 3" inners
Just to clarify....
actual bolt thread size is 3/8"-16, bolt head size is 9/16"
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Old 11-28-2008, 12:07 PM   #10
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Re: Exhaust Manifold Bolt Sizes

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Originally Posted by Cyclone View Post
Just to clarify....
actual bolt thread size is 3/8"-16, bolt head size is 9/16"
OOPS



thanks for the correction
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Old 11-28-2008, 03:54 PM   #11
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Re: Exhaust Manifold Bolt Sizes

That's the only thing I WAS sure of
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Old 12-18-2008, 04:10 AM   #12
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Re: Exhaust Manifold Bolt Sizes

Actually....those are not the correct lengths for my stock 350....I just went through this...I initially used the 2.5" & 3" lengths, but I wound up bottoming out in several of the holes before they tightened....

I then ordered a correct kit from one of our site vendors and they came in 8 ea. @ 2.25" & 4 ea. @ 2.75" (centers).....they were perfect!

It's my understanding that you do not ever want to bottom out like that as you can cause major damage...

Dan
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Old 12-18-2008, 06:39 AM   #13
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Re: Exhaust Manifold Bolt Sizes

What is the grade # of the bolts?
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Old 12-19-2008, 07:15 PM   #14
mbgmike
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Re: Exhaust Manifold Bolt Sizes

Quote:
Originally Posted by Rack Man View Post
Actually....those are not the correct lengths for my stock 350....I just went through this...I initially used the 2.5" & 3" lengths, but I wound up bottoming out in several of the holes before they tightened....

I then ordered a correct kit from one of our site vendors and they came in 8 ea. @ 2.25" & 4 ea. @ 2.75" (centers).....they were perfect!

It's my understanding that you do not ever want to bottom out like that as you can cause major damage...

Dan
Yeah the manifolds must be differant cause I pulled the bolts on a stove stock 350 with stock manifolds also just before I posted the lengths
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