Header bolt question

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Sep 19, 2008 | 04:17 PM

addballer696

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Racer

Joined: Nov 2006

Posts: 357

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From: Champaign Urbana IL

Header bolt question

what size and grade, ect. of bolts should I use to bolt headers to a 350.

Sep 19, 2008 | 04:37 PM

burners

Le Mans Master

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From: Brazos TX

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3/8-16x3/4 long. Any parts store will have them. Trans-Dapt or Mr. Gasket are the most common brands carried.
http://store.summitracing.com/partde...5&autoview=sku
http://store.summitracing.com/partde...1&autoview=sku
http://store.summitracing.com/partde...1&autoview=sku

Sep 19, 2008 | 04:39 PM

addballer696

Thread Starter

Racer

Joined: Nov 2006

Posts: 357

Likes: 8

From: Champaign Urbana IL

I gotta pick these up today at a hardware store because tonight I'll be putting on sidepipes. You think 3/4 is big enough or should I go with 1 inch?

Sep 19, 2008 | 10:32 PM

Scott Marzahl

Le Mans Master

Joined: Apr 2005

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From: Seattle Area WA

3/4" and make sure they are grade 8 minimum or they will break from heat fatigue.

Sep 20, 2008 | 10:34 AM

AimHigh

Drifting

Joined: May 2008

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From: Choctaw Country

Quote:

Originally Posted by Scott Marzahl

3/4" and make sure they are grade 8 minimum or they will break from heat fatigue.

Do it correctly now or you'll be paying for it later up under the hood....

Sep 20, 2008 | 01:22 PM

7T1vette

Team Owner

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From: Crossville TN

I don't think 3/4" bolts will "get it". The outer 4 bolts are 2" long; the middle 2 bolts are 2-3/4". All are Grade 8 bolts. Put a bit of anti-seize compound on the threads so you can remove them 5 years from now.

Sep 20, 2008 | 03:47 PM

Rolling Thunder

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From: Paducah KY

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St. Jude Donor '03

Quote:

Originally Posted by 7T1vette

You may be right if he is installing cast exhaust manifold like original, but he said headers. All bolts should be the same length, 3/4".

Sep 20, 2008 | 04:44 PM

Dustup7T2

Terrorizing Orange Cones

Joined: Oct 2007

Posts: 2,572

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From: Northern CO

Be sure to retighten after a few heat-cold cycles. Header bolts tend to loosen up sooner than you'd hoped and it'll save burning through the header gasket and creating another problem.

Suggestion for the anti-seize is experience & knowledge speaking, even on iron heads and especially on aluminum. Cheap insurance.