Header bolts questions
Thread Starter
Melting Slicks
Joined: Feb 2009
Posts: 2,857
Likes: 234
From: SW Nuh Hampsha
2018 C5 of Year Finalist
Header bolts questions
I just picked up a nice set of used B&B shorty headers that I'll be installing in my '98. I want to buy new bolts for both the head-side and the collector side. Can anyone tell me the size of these? Also, I might as well replace those small air tube bolts, too. Size on those?
I was thinking about using stainless steel bolts just for peace of mind. Is this a good idea for this application? I don't know if the extreme heat will affect the integrity of stainless or not. I'm trying to avoid future corrosion issues, if that makes any sense.
Lastly, should I be using flat and/or lock washers on either end of the headers? I've heard that some people have trouble keeping their headers tightly bolted, at one and or the other. I would like to do this right the first time. Thanks!
I was thinking about using stainless steel bolts just for peace of mind. Is this a good idea for this application? I don't know if the extreme heat will affect the integrity of stainless or not. I'm trying to avoid future corrosion issues, if that makes any sense.
Lastly, should I be using flat and/or lock washers on either end of the headers? I've heard that some people have trouble keeping their headers tightly bolted, at one and or the other. I would like to do this right the first time. Thanks!
Le Mans Master
Joined: May 2007
Posts: 5,393
Likes: 17
From: Belleville Mich.
Just reuse your header & air tube bolts.
Wire brush the threads of each bolt & apply plenty of anti seize on all the above mentioned bolts, prior to reinstalling.
Retighten with two passes. 1st @ 11 lb ft & 2nd @ 15 lb ft.
Buy new air tube gaskets (2) GM# 12553617
Put a slight fim of anti seize on both sides, before install.
Tighten to 15 lb ft.
Each header system has different variences, in regards to clips, bell housing hangars & clamps.
Do plkenty of "searches" pertaining to the perticular system your about to install, prior to install .
It will make things go much smoother/easier, & less hassel.
Good luck.
Wire brush the threads of each bolt & apply plenty of anti seize on all the above mentioned bolts, prior to reinstalling.
Retighten with two passes. 1st @ 11 lb ft & 2nd @ 15 lb ft.
Buy new air tube gaskets (2) GM# 12553617
Put a slight fim of anti seize on both sides, before install.
Tighten to 15 lb ft.
Each header system has different variences, in regards to clips, bell housing hangars & clamps.
Do plkenty of "searches" pertaining to the perticular system your about to install, prior to install .
It will make things go much smoother/easier, & less hassel.
Good luck.
Thread Starter
Melting Slicks
Joined: Feb 2009
Posts: 2,857
Likes: 234
From: SW Nuh Hampsha
2018 C5 of Year Finalist
Thanks for your input, Bumble-Z.
What about the three bolts on the collector end? Don't the stock manifolds have studs in them there? The B&Bs have holes, so I'll need some bolts, nuts & washers there. I can figure out what size to use there, but I'd still like to know if stainless hardware is acceptable in exhaust applications.
While we're talking about the collector end, are there flat gaskets that go there, or does it take a doughnut type of seal?
What about the three bolts on the collector end? Don't the stock manifolds have studs in them there? The B&Bs have holes, so I'll need some bolts, nuts & washers there. I can figure out what size to use there, but I'd still like to know if stainless hardware is acceptable in exhaust applications.
While we're talking about the collector end, are there flat gaskets that go there, or does it take a doughnut type of seal?
Le Mans Master
Joined: May 2007
Posts: 5,393
Likes: 17
From: Belleville Mich.
Thanks for your input, Bumble-Z.
What about the three bolts on the collector end? Don't the stock manifolds have studs in them there? The B&Bs have holes, so I'll need some bolts, nuts & washers there. I can figure out what size to use there, but I'd still like to know if stainless hardware is acceptable in exhaust applications.
While we're talking about the collector end, are there flat gaskets that go there, or does it take a doughnut type of seal?
What about the three bolts on the collector end? Don't the stock manifolds have studs in them there? The B&Bs have holes, so I'll need some bolts, nuts & washers there. I can figure out what size to use there, but I'd still like to know if stainless hardware is acceptable in exhaust applications.
While we're talking about the collector end, are there flat gaskets that go there, or does it take a doughnut type of seal?
My system (LG Long Tube Pro's, with LG 3' X pipe) has a slip fit at the collector & 3" x pipe, held together by an exhaust band clamp.
On my system I applied anti sieze @ each & every slip fit, before clamping. Makes it easier when removal if needed.
I suggest getting hold of BB They will be the one to correctly answer your questions in regards to your BB Shorties.
They have a great cust, serv/relations.
Good luck.
Pro
Joined: Mar 2004
Posts: 653
Likes: 0
Header and manifold bolts like to vibrate loose. Not sure about your flange thickness, but for factory manifolds I found these bolts and spiffy Nord lock-washers do an excellent job of retaining torque...even when the bolt threads are slathered in anti-seize:
From McMaster-Carr: http://www.mcmaster.com/
91812A430 Type 316 Stainless Steel Wedge Lock Washer, 5/16"/M8 Screw Size, .65" OD, .09"
92290A434 Metric 316 Stainless Steel Socket Head Cap Screw, M8 Thread, 30mm Length, 1.25mm Pitch
You might want bolts in 25mm or 20mm length if the header flange plates are thinner than manifold pieces, take a measurement and you'll be all set.
From McMaster-Carr: http://www.mcmaster.com/
91812A430 Type 316 Stainless Steel Wedge Lock Washer, 5/16"/M8 Screw Size, .65" OD, .09"
92290A434 Metric 316 Stainless Steel Socket Head Cap Screw, M8 Thread, 30mm Length, 1.25mm Pitch
You might want bolts in 25mm or 20mm length if the header flange plates are thinner than manifold pieces, take a measurement and you'll be all set.
Pro
Joined: Mar 2004
Posts: 653
Likes: 0
Adding to this, tighten the header/manifold bolts in sequence from the center outward per the GM manual. This allows the gasket to smooth out as it's compressed between the head and manifold, and not get a wrinkle in it that will interfere w/ sealing.
Le Mans Master
Joined: Dec 2000
Posts: 5,245
Likes: 25
From: Blue Ridge Georgia
I've been thru a number of different headers over the years. I only use the header bolts that have the Allen screw in the center of the bolt head. Those will not work loose. I have used them all, and they work loose other than the ones with the Allen screw.
Pro
Joined: Mar 2004
Posts: 653
Likes: 0
The ones I listed above are allen head types, I use them w/ a long bit as it's easier to reach with fat header primaries. (McMaster sells those in 3/8" drive, also.)
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Drifting
Joined: Oct 2006
Posts: 1,773
Likes: 2
From: San Diego CA
When I installed my B&B shorties I reused the stock air tube bolts (cleaned & lubed as mentioned above), but I used ARP headers studs.
I used the header studs because I installed the headers myself. With the header studs, I was able to hang the gasket, then the header on the studs. That made it easy to start the nuts, with the gasket & header held in place.
Just a thought.....
Good luck with the install.......
I used the header studs because I installed the headers myself. With the header studs, I was able to hang the gasket, then the header on the studs. That made it easy to start the nuts, with the gasket & header held in place.
Just a thought.....
Good luck with the install.......
Thread Starter
Melting Slicks
Joined: Feb 2009
Posts: 2,857
Likes: 234
From: SW Nuh Hampsha
2018 C5 of Year Finalist
Thank you, gentlemen! All good info here.
I would have thought the Allen-head bolts would be difficult to access, using a regular Allen L-shaped "wrench", but didn't think about an Allen drive for a ratchet.
And, using studs rather than bolts, I would have been worried about having enough clearance in getting the header flange onto the studs. Apparently that's not an issue either.
It looks like I could go either way there, as well as re-using the original bolts.
Decisions, decisions.
I appreciate the input from all of you!
I would have thought the Allen-head bolts would be difficult to access, using a regular Allen L-shaped "wrench", but didn't think about an Allen drive for a ratchet.
And, using studs rather than bolts, I would have been worried about having enough clearance in getting the header flange onto the studs. Apparently that's not an issue either.
It looks like I could go either way there, as well as re-using the original bolts.
Decisions, decisions.
I appreciate the input from all of you!
Melting Slicks
Joined: Oct 2007
Posts: 2,798
Likes: 8
From: It's true money can't buy happiness, but it is more comfortable crying in a Corvette than on a bicyc
St. Jude Donor '13
I spent the extra money and bought Stage 8 Fasteners. It's a brand of special header bolts with a c clip locking system. Months later I still haven't put on 6 out of 8 of the locks. The bolts haven't loosened so there's no hurry on my part. They use allen or hex head. The whole exhaust system is stainless and there are no issues.
Le Mans Master
Joined: Aug 2005
Posts: 5,375
Likes: 328
From: CA.
St. Jude Donor '13-'14-'15
I always use the Stock GM header bolts--They come with some blue compund on the threads and have never had any problems with LT's--I never re-use the old bolts-Also--I have found that the Stock 3 layer GM gaskets seem to work the best-I never use the provided gaskets on LT's--The GM gaskets are a one-time use as well--
Burning Brakes
Joined: Aug 2007
Posts: 989
Likes: 14
From: Hewitt, TX
I actually installed BBK shorties last night. I had to buy 4 new header to exhaust bolts (the three at the bottom of the header). The darn things are like 13 bucks each at the dealer (PN# 12562640)
