Exhaust manifold bolts? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Low84 · 11-05-2013, 11:49 PM

Where are you guys getting them from? I went to O'Reilys and Autozone and both want to sell me m10 x 1.5. I am under the impression that it's supposed to be a m8 x 1.25. They both told me I was wrong and those were ford bolts. I bought the m10 and they were indeed too big?

What's the right size and where do you guys get them from?

BR3W CITY · 11-06-2013, 01:46 AM

From manifold to collector flange
or
from head to header flange?

smoky02 · 11-06-2013, 02:29 AM

Seems like I ordered mine off of Amazon...or maybe they came with my headers...go to LS1truck, or LS1tech, and check in the for sale threads, I'm sure someone there can hook you up.

Wasted Income · 11-06-2013, 09:36 AM

M8 x 1.25 thread. Dorman part # 03413B GM part # 11518860

The earlier engines had bolts that fit a 10mm socket. The newer engines use bolts that fit a 13 mm socket.

Billett · 11-06-2013, 07:44 PM

Mine came with the headers, but they are indeed M8x1.25. ARP sells a set for $30

Low84 · 11-06-2013, 10:55 PM

I should have mentioned it earlier. Yes, head to flange

Thanks for the help fellas, especially for part #'s

BigRed76 · 11-07-2013, 04:06 PM

I've seen way too many factory exhaust manifold bolts broken on LS engines, I'd go with the ARP's...you can get them from Summit, JEGS, Speedway, etc.

Billett · 11-07-2013, 05:44 PM

I actually put a small dab of anti-seize on the tips then check the torque every time I do an oil change. Takes another 10 mins and I rarely have one back out, but at least I know they'll be easier to get out of the aluminum when I need them to.

Wasted Income · 11-08-2013, 10:55 AM

^ LOL....damn man. Taking preventative maintenance to a new level.

I rip them down with the cordless impact, go out and beat on the truck till the manifolds are glowing red....rinse and repeat.

Never broken a manifold bolt on any of the 6 LS swaps I've done. However it's weird how almost every swap engine I start with has at least one broken bolt...usually the one on the driver side closest to the firewall.

crazy longhorn · 11-10-2013, 11:13 PM

Quote:

Originally Posted by Low84

Where are you guys getting them from? I went to O'Reilys and Autozone and both want to sell me m10 x 1.5. I am under the impression that it's supposed to be a m8 x 1.25. They both told me I was wrong and those were ford bolts. I bought the m10 and they were indeed too big?

What's the right size and where do you guys get them from?

Did you find what you need....or need a set? I have a set that came with the hooker headers(3/8", thick flanges)....should be about right for your stock manifolds? I went studs/nuts on mine...if you need the bolts, shoot me a PM, & I will mail em to you. Longhorn

Low84 · 11-12-2013, 01:02 AM

Thanks. Yeah I did. I Couldn't get the people at the store to find it with part number and all. Online shipping was more expensive than the bolts so I just went with the ARP from Jegs with free shipping.

crazy longhorn · 11-12-2013, 02:45 AM

Good deal....the studs/nuts were not cheap (stainless), about 125 for the set (ouch), but I will probably pull the headers once a season for blast/repaint. Longhorn

solidaxel · 11-14-2013, 11:28 AM

Quote:

Originally Posted by crazy longhorn

Good deal....the studs/nuts were not cheap (stainless), about 125 for the set (ouch), but I will probably pull the headers once a season for blast/repaint. Longhorn

Are there no Jet Hot coating companies in your area, or are you against coatings, seems like a lot of work

crazy longhorn · 11-14-2013, 08:22 PM

No coaters in my area , that I know of? As far as the work....its a labor of love

29 yrs, I have played with that old truck, many other toys also (sandrail,motorcycles,5.0 stang, several trucks...including a v8 swap in both S-10 & ranger.... The 69 was the only one I have kept that long! I guess that the blood runs deep

Longhorn

11-05-2013, 11:49 PM	#1
Low84 Registered User Join Date: Oct 2004 Location: Roma,TX Posts: 774	Exhaust manifold bolts? Where are you guys getting them from? I went to O'Reilys and Autozone and both want to sell me m10 x 1.5. I am under the impression that it's supposed to be a m8 x 1.25. They both told me I was wrong and those were ford bolts. I bought the m10 and they were indeed too big? What's the right size and where do you guys get them from? __________________ 1978 stepside C10 build: http://67-72chevytrucks.com/vboard/s...d.php?t=468265

11-06-2013, 01:46 AM	#2
BR3W CITY meowMEOWmeowMEOW Join Date: Sep 2009 Location: MKE WI Posts: 7,128	Re: Exhaust manifold bolts? From manifold to collector flange or from head to header flange? __________________ *'66 Short Step / SD Tuned / Big Cam LQ4 / Backhalfed /Built 4l80e / #REBUILDEVERYTHING* MY BUILD THE H8RDCPTR //\\ MY YOUTUBE CHANNEL REV J HD

11-06-2013, 02:29 AM	#3
smoky02 Registered User Join Date: Oct 2003 Location: Sunny, Florida, some might call it South Alabama Posts: 834	Re: Exhaust manifold bolts? Seems like I ordered mine off of Amazon...or maybe they came with my headers...go to LS1truck, or LS1tech, and check in the for sale threads, I'm sure someone there can hook you up. __________________ Just sold my C10...sad day... Looking for a 1972 Blazer to hopefully fill the hole in my heart.

11-06-2013, 09:36 AM	#4
Wasted Income Boosted Member Join Date: May 2002 Location: Mackinaw, IL Posts: 2,200	Re: Exhaust manifold bolts? M8 x 1.25 thread. Dorman part # 03413B GM part # 11518860 The earlier engines had bolts that fit a 10mm socket. The newer engines use bolts that fit a 13 mm socket. __________________ 1972 2wd K/5 Blazer Turbocharged 370 LSx - 941 rwhp / 1093 rwtq 1969 Chevy K-10 L33 5.3 / 4L80E / NP241 / 4" lift 1964 Buick Skylark Twin TURBO 383 LS pro-touring project 2014 VW Passat TDI - Daily Driver Turbo diesel 2015 Sierra Denali HD Duramax Turbo diesel 2023 Ford Explorer ST - Twin Turbskis 2023 Ford F150 RCSB - Whipple Supercharged 2017 Polaris RZR Turbo 2014 Nor-Tech Center Console - Twin Supercharged Outboards *TURBO ALL THE THINGS!!*

11-06-2013, 07:44 PM	#5
Billett Registered User Join Date: Jun 2012 Location: Pittsgrove, NJ Posts: 1,502	Re: Exhaust manifold bolts? Mine came with the headers, but they are indeed M8x1.25. ARP sells a set for $30 __________________ Will 1968 C10 - Project Texa Go 6.0/4L80e 2003 Mitsubishi Lancer Evolution 2002 Ford Excursion 7.3L 2024 Toyota Sienna

11-06-2013, 10:55 PM	#6
Low84 Registered User Join Date: Oct 2004 Location: Roma,TX Posts: 774	Re: Exhaust manifold bolts? I should have mentioned it earlier. Yes, head to flange Thanks for the help fellas, especially for part #'s __________________ 1978 stepside C10 build: http://67-72chevytrucks.com/vboard/s...d.php?t=468265

11-07-2013, 04:06 PM	#7
BigRed76 Registered User Join Date: Jan 2010 Location: Loveland, CO Posts: 1,921	Re: Exhaust manifold bolts? I've seen way too many factory exhaust manifold bolts broken on LS engines, I'd go with the ARP's...you can get them from Summit, JEGS, Speedway, etc. __________________ Zach 1970 Chevrolet Custom Camper K20 1971 GMC Super K2500, 12V/NV4500 swap in progress 1971 Chevrolet Custom C10 1972 Chevrolet Custom Deluxe C20, 5.3/4L60E 1972 Oldsmobile Cutlass Supreme, 455/TH400, 3.73 posi 2004 GMC Sierra 2500HD, LB7/Allison, CCSB 2005 GMC Sierra 1500, 5.3/4L60E, CCSB

11-07-2013, 05:44 PM	#8
Billett Registered User Join Date: Jun 2012 Location: Pittsgrove, NJ Posts: 1,502	Re: Exhaust manifold bolts? I actually put a small dab of anti-seize on the tips then check the torque every time I do an oil change. Takes another 10 mins and I rarely have one back out, but at least I know they'll be easier to get out of the aluminum when I need them to. __________________ Will 1968 C10 - Project Texa Go 6.0/4L80e 2003 Mitsubishi Lancer Evolution 2002 Ford Excursion 7.3L 2024 Toyota Sienna

11-08-2013, 10:55 AM	#9
Wasted Income Boosted Member Join Date: May 2002 Location: Mackinaw, IL Posts: 2,200	Re: Exhaust manifold bolts? ^ LOL....damn man. Taking preventative maintenance to a new level. I rip them down with the cordless impact, go out and beat on the truck till the manifolds are glowing red....rinse and repeat. Never broken a manifold bolt on any of the 6 LS swaps I've done. However it's weird how almost every swap engine I start with has at least one broken bolt...usually the one on the driver side closest to the firewall. __________________ 1972 2wd K/5 Blazer Turbocharged 370 LSx - 941 rwhp / 1093 rwtq 1969 Chevy K-10 L33 5.3 / 4L80E / NP241 / 4" lift 1964 Buick Skylark Twin TURBO 383 LS pro-touring project 2014 VW Passat TDI - Daily Driver Turbo diesel 2015 Sierra Denali HD Duramax Turbo diesel 2023 Ford Explorer ST - Twin Turbskis 2023 Ford F150 RCSB - Whipple Supercharged 2017 Polaris RZR Turbo 2014 Nor-Tech Center Console - Twin Supercharged Outboards *TURBO ALL THE THINGS!!*

11-12-2013, 01:02 AM	#11
Low84 Registered User Join Date: Oct 2004 Location: Roma,TX Posts: 774	Re: Exhaust manifold bolts? Thanks. Yeah I did. I Couldn't get the people at the store to find it with part number and all. Online shipping was more expensive than the bolts so I just went with the ARP from Jegs with free shipping. __________________ 1978 stepside C10 build: http://67-72chevytrucks.com/vboard/s...d.php?t=468265

11-12-2013, 02:45 AM	#12
crazy longhorn Fabricate till you "puke" Join Date: Jun 2002 Location: Ill Posts: 9,402	Re: Exhaust manifold bolts? Good deal....the studs/nuts were not cheap (stainless), about 125 for the set (ouch), but I will probably pull the headers once a season for blast/repaint. Longhorn __________________ 69 longhorn,4" chop,3/5 drop, 1/2 ton suspension/disc brakes,1 1/2" body drop,steel tilt clip, 5.3/Edelbrock rpm intake/600 carb, Hooker streetrod shorties,2 1/2" exhaust/ H pipe/50's Flows , 6 spd Richmond trans,12 bolt/ 3.40 gears....

11-14-2013, 08:22 PM	#14
crazy longhorn Fabricate till you "puke" Join Date: Jun 2002 Location: Ill Posts: 9,402	Re: Exhaust manifold bolts? No coaters in my area , that I know of? As far as the work....its a labor of love 29 yrs, I have played with that old truck, many other toys also (sandrail,motorcycles,5.0 stang, several trucks...including a v8 swap in both S-10 & ranger.... The 69 was the only one I have kept that long! I guess that the blood runs deep Longhorn __________________ 69 longhorn,4" chop,3/5 drop, 1/2 ton suspension/disc brakes,1 1/2" body drop,steel tilt clip, 5.3/Edelbrock rpm intake/600 carb, Hooker streetrod shorties,2 1/2" exhaust/ H pipe/50's Flows , 6 spd Richmond trans,12 bolt/ 3.40 gears....



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