Exhaust Manifold bolt sizes

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Mar 23, 2004 | 08:51 PM

79MakoL82

Thread Starter

Melting Slicks

Joined: Nov 2000

Posts: 2,663

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From: Palm Harbor FL

Exhaust Manifold bolt sizes

I'm replacing my cracked driver side exhaust manifold and decided that while I'm at it, I'll replace all the manifold bolts with some good Grade 8's. I know they are of different lengths. Is there a anyone who sells them as a package, or can someone tell me what the sizes I need and I'll run down to Lowe's.

It's for a 1979 with stock rams horns and a/c.

Any help would be appreciated.

Mar 24, 2004 | 09:50 AM

greg454

Burning Brakes

Joined: Jul 2001

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From: Foxfield, Co

Re: Exhaust Manifold bolt sizes (79MakoL82)

I just installed my exhaust manifolds the other day, and i'm not sure what size the bolts are (some are just studs that accessories also mount to) but what I can tell you is that the torque specs were only 20ft/lbs. Grade 8 is extreme overkill.

Greg

Mar 24, 2004 | 10:21 AM

markdtn

Le Mans Master

Joined: Aug 2003

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From: Chattanooga TN

Re: Exhaust Manifold bolt sizes (greg454)

I think Paragon sells them in a package. I'd look but my desk drawer decided to lock itself and I can't get in. Have to wait for Maintenance to open it again. I think that there are four 2 1/4" and two 2 1/2' on each side, but not positive. Some are "special" with studs on top.

Mar 24, 2004 | 10:31 AM

BB wowbagger

Melting Slicks

Joined: Feb 2002

Posts: 2,298

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From: Sodertalje/Sweden

Re: Exhaust Manifold bolt sizes (markdtn)

How about a set of ARPs? :cheers: :cool:

These are kinda :cool: http://www.jegs.com//cgi-bin/ncommer...62&prmenbr=361

[Modified by BB wowbagger, 4:41 PM 3/24/2004]

Mar 24, 2004 | 10:53 AM

Paul L

Team Owner

Joined: Aug 1999

Posts: 30,995

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From: Ontario

Re: Exhaust Manifold bolt sizes (79MakoL82)

Here is a set for a stock 1979. The shorter are 2 1/4" from below head to end and the longer 2 3/4". The oddball one is for the A/C: front on passenger side. I believe (but cannot confirm) that it is used also to fasten that choke heat stove on the drivers side. You can see the mount hole reinforced with a washer.

There are eight SS, thick washers used with the shorter bolts only. In addition four french locks are used per car. Hope this helps.

Mar 24, 2004 | 11:19 AM

NHvette

Le Mans Master

Joined: Jun 2002

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From: I can walk to MA

Re: Exhaust Manifold bolt sizes (greg454)

Quote:

Grade 8 is extreme overkill.

600 cubic inches is definitely extreme overkill
Are grade 8 bolts ? Well, maybe.
I use grade 8 everywhere. Not only are they stronger, but they hold up to the
elements much better than lesser grades.
Well worth the extra 50 cents each to be able to remove them in a few years.

:seeya

Mar 24, 2004 | 02:33 PM

Fevre

Race Director

Joined: Mar 2001

Posts: 11,322

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From: Living in the Hartland

Re: Exhaust Manifold bolt sizes (NHvette)

Grade 8 as nice in case they seize up, less chance of snapping off.

Mar 24, 2004 | 09:14 PM

79MakoL82

Thread Starter

Melting Slicks

Joined: Nov 2000

Posts: 2,663

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From: Palm Harbor FL

Re: Exhaust Manifold bolt sizes (paul67)

Thanks guys.

I've seen sets for headers, but nothing packaged for stock manifolds.

I know grade 8's are probably overkill, but what the hey. Not really gonna harm anything. The sieze issue is the reason I was thinking of going with the grade 8's. I've heard a few horror stories of bolts seizing up in the block, so I thought I'd go with a stronger bolt. I do intend to eventually remove the manifolds and go with headers, so I'm trying an ounce of prevention now.

Thanks again. :cheers:

[Modified by 79MakoL82, 9:15 PM 3/24/2004]