header gaskets

[grumpyvette]

if the header flange is strait and flat and your using a decent header gasket youll rarely have problems with any material,(personally I prefer the copper ones) and if youve coated the bolt or stud threads in the heads with ANTI-SEIZE like you should have, almost any decent 6"-8" box end wrench can be used to snug the bolts or nuts on the studs up firmly.
but at times youll want those header bolts or socket head cap screw bolts
due to clearance or tool access issues, but if you can use STUDS as they provide a better clamp force and are far less likely to screw up the threaded holes in the cylinder heads

on aluminum head its almost alway's best to use studs to secure headers when you can,
as a stud has the threads full length engaged and very low stress , and significantly more surface area spreading the load,
than a bolt will ever allow,

STAR LOCK WASHERS GO BETWEEN THE CLAMP WASHER AND STUD NUTS
this is very common on some heads and the brand of header , its gasket flange design and the type of exhaust gasket used effects your results, paper or paper with metallic foil composite gaskets tend to burn thru if not 100% evenly clamped, as the least leak allows burn thru,copper header gaskets and use of proper bolts on the header flange tends to help, anti seize on the threads helps
http://www.summitracing.com/parts/MRG-3409/?rtype=10

http://www.summitracing.com/parts/SUM-111405/

http://garage.grumpysperformance.com/index.php?threads/sources-for-headers.1247/

http://garage.grumpysperformance.com/index.php?threads/building-custom-headers.961/


http://www.stage8.com

http://store.summitracing.com/partdetail.asp?part=ARP-400-1101&autoview=sku

I would strongly suggest BOTH stainless bolts studs and the use of ANTI SEIZE on the threads

http://store.summitracing.com/partdetail.asp?autofilter=1&part=SUM-SP1502&N=700+324400+115&autoview=sku

http://store.summitracing.com/egnsearch.asp?N=700+115+317370&D=317370


I think youll find that in some applications socket head cap screws are easier to use/install

if your having a difficult time accessing the header bolts due to wrench or socket clearance issures

try 12 point metric sockets also, once thier out out replace all the bolts with stainless socket head cap screws, and use anti seize on the threads, with star lock washers under thier heads

 

[lsejlowe]

so what's the best source for socket head cap screws for headers? I don't think I'll be able to find SS socket heads at local hardware shops, but maybe the typical black oxide coating will be good enough?

 

[grumpyvette]

black oxide coated work ok, but many hardware stores do have stainless 3/8" NC 1.25" cap screws


READ THIS
viewtopic.php?f=56&t=4541&p=12105&hilit=header+gaskets#p12105

viewtopic.php?f=56&t=4541&p=13522&hilit=copper+header#p13522

 

[JumpRun]

Have a header install coming, so I thought this might be a good post to get a sanity check.

I have a set of LG Pro long tube headers and went with their recommendation to use the stock LS1 gaskets rather than the LS6 gasket, (I have an LS6-2002 Z06). I understand this is due to the port size relative to the header as opposed to the stock manifold.

The headers have nice thick flanges, and I've yet to get header bolts. I've read some people just reuse the stock ones. I've yet to get any but have been leaning towards some ARP SS ones, probably from summit. So I'm still pondering stock or aftermarket.

Being in California I'm stuck with the smog tests, I have high flow converters with the new system and a good shop for smog checks so I just need to pass the computer. I was thinking with a bit over 65K miles on the car new O2 sensors might be a good Idea while I'm at it. Do these things wear? I have only had it tested once and it was fine, but I'm on a two year cycle now so I'm considering new ones. How about brands, should I stay with stock GM sensors ? Plus there are 4 of them and I've seen some people say the block some off? I do plan on getting a tune after the install but don't want to deal with any more codes than I have to as well as keep all the stock smog stuff intact. I'm aware that the location change on the converter is bumping the rules as is not having a CARB aproval, but I'm not worried about a visual inspection, just the sniffer. I'll also be running my stock titanium mufflers.

Comments and suggestions welcomed.

Thanks in advance.
gb

 

[grumpyvette]

If your forced to replace the sensors, most guys prefer the bosch sensors

http://www.boschautoparts.com/Products/OxygenSensors/

as they seem to last a long time,
personally Id suggest pulling codes before the test just to see if any sensors defective, and only replacing them IF necessary because they are not dirt cheap. Id also point out that a bit of ANTI-seize on the threads makes removal far easier after years of heat cycles,

as to the bolts, measure the threaded hole depth in the heads and get bolts that have a 3/4-7/8 of depth, of thread engagement
example
if the threaded holes in the heads measured 1" deep the header flange is 3/8" thick and the gaskets are .120, (1.495" total depth) that's ideally requires a bolt that's about 1.25"-1.375" long because a 1.5" bolt might bottom out and strip threads before the correct clamp loads are applied, and BOLTS generally come in 1/4" length increases in sizes, in that range of smaller diam.
keep in mind the bolt diam. is about 3/8" so anything exceeding 1.5 times its diam. to twice its diam. ( 3/8" +3/8"=3/4") in thread engagement or more is unlikely to strip in aluminum PROVIDED the clamp loads are NOT applied until the threads almost fully engaged, and its not cross threaded, now in an ideal world you use STUDS because you thread those to just short of full depth, and aluminum is softer than steel , and requires more thread depth, and you install those finger tight for full thread engagement before ANY clamping loads are applied and if the threaded length were 1.5" or 1.75" the full thread carry's the clamp loads regardless as theres a nut applying the clamp loads and the total stud length is not as critical

 

[JumpRun]

Thanks,
I have considered studs rather than bolts but recall reading about difficulty getting the headers over them.

So if the O2's aren't broke don't fix'em then. I've been on the anti seize for a long time, great stuff.



Thanks again.

 

[grumpyvette]

studs are much superior to bolts, and they can be installed just like bolts by use of two nuts installed on the last outer threads on the stud,and tightened against each other to allow a wrench to thread them into the heads giving full thread contact and then the two nuts are loosened, and one tightened against the header flange to get the clamp loads correct.
OR there are studs that are designed to use an allen key for installation, That way you avoid the clearance issue of studs sticking out of the heads during the installation but have the full advantage of studs extra strength.
yes its a bit more work but its generally much stronger also and less likely to strip threads in expensive heads, because no clamp loads are applied until full thread engagement is achieved, naturally the correct thread and length must be selected, and the studs must be screwed in to max depth with the threads coated with ANTI-SEIZE COMPOUND, before any clamp loads are applied
Ive used the standard cap screw bolts with washers and Anti-seize on the threads and no lock washer and copper exhaust gaskets and have had zero issues

Ive always found the STAR LOCK WASHERS, under the nuts , and used with the studs was all that's required, on the rare sets of headers on some cars that do occasionally seem to need to be re-tightened occasionally, I generally don,t get overly concerned with exact torque loads I just tighten them about as tight as I can get the nuts with a short box end wrench and have not had any problems

http://www.alliedbolt.com/threadedstudsandrod.html

http://www.reidsupply.com/GrpResults.as ... 021997&bi=

http://www.jegs.com/i/Spectre/865/4665/ ... tId=756827

.

 

[DorianL]

studs or locking bolts for headers

Getting my headers on are a real pain. Lining up the bolts are one thing but tightening is a pain too. I need to tighten them all gradually else they interfere with the primaries. So I am thinking these:

Tho' I'd hate to see them break off in my heads...

I also HATE header bolts coming loose as the ALWAYS seem to do with me. So on other hand, I am thinking about these:

What do you guys think?

D.

 

[grumpyvette]

Re: studs or locking bolts for headers

ease of tool access to the studs or bolts tends to be the deciding factor in many installations,socket head cap screws with a coat of anti-seize paste on the threads are a common practice as they allow the use of the ball head allen drivers that make access in tight confines a bit easier.
A set of stainless studs can also be used in some applications as studs put a great deal less wear and stress on the threaded holes in the heads,because they are threaded into place to full depth , with some anti-seize on the threads,BEFORE any tightening stress loads are applied, this is a huge factor in prolonged durability in softer aluminum heads especially when the holes in the headers are not exactly aligned, you might be amazed at how ofter even quality headers have one or more bolt holes that are a bit out of alignment, , like most guys Ive always assumed headers should just bolt up with a decent gasket between the header flange and the heads but in many cases the header flange is a bit warped or the holes need a bit of tweaking like having a slightly larger drill size run thru the hole to allow quick easy installation.
if youve got the room studs at least on the two end locations to make installing the headers far easier is a good idea
many guys use bolts to DRAW a warped header firmly against a head, this puts a great deal of stress on the threads and in many cases the threads not in to at least 1.5 times its diameter before the stress loads are applied so you get mis-aligned or stripped threads in the heads
its really best to use a clean-up bottom tap to clean threads and some solvent and high pressure air to blow out debris, before test threading the studs or bolts BEFORE trying to install headers.


http://www.imperialinc.com/pdf/I_Tap&DieChart.pdf

http://www.harborfreight.com/air-blow-g ... 42939.html

http://www.summitracing.com/parts/EAR-D026ERL/?rtype=10

viewtopic.php?f=79&t=1046&p=1951&hilit=+copper+header#p1951

viewtopic.php?f=27&t=1262&p=6142&hilit=taps+clean#p6142

viewtopic.php?f=56&t=559&p=713&hilit=+copper+header#p713

 

[DorianL]

Re: studs or locking bolts for headers

Hmmm, were I to use studs... is there anyway to prevent them from working themselves loose? Seems to me I am always retightening header bolts...

 

[grumpyvette]

Re: studs or locking bolts for headers

When I use studs on headers, Ive never had any problem at all, but then I use star lock nuts and copper exhaust gaskets,with star locks under the nuts, and put a dab of gasket cement on the nuts threads to keep the nuts secure, if I find they are coming loose
Ive generally used studs on the outer two exhaust bolts and use those two locations to line up the gasket and headers, Ive used studs on any and all locations that will allow their use regarding clearance during any header install, because I feel studs are superior, but on a corvette clearance issues prevent you from using just studs and theres at least 2-4 locations per side that require bolts, on those locations I prefer stainless socket head cap screws , because its generally easier to get an Allen key into the bolts than a socket around the bolt head,again due to clearance access
this is very common on some heads and the brand of header , its gasket flange design and the type of exhaust gasket used effects your results, paper or paper with metalic foil composite gaskets tend to burn thru if not 100% evenly clamped, as the least leak allows burn thru,copper header gaskets and use of proper bolts on the header flange tends to help, anti seize on the threads helps
http://www.summitracing.com/parts/MRG-3409/?rtype=10

MR GASKET MAKES RECESSED HEAD HEADER BOLTS MANY GUYS PREFER
http://www.summitracing.com/parts/SUM-111405/

http://www.almabolt.com/pages/catalog/washers/star.htm

viewtopic.php?f=44&t=700&p=973&hilit=sealant+silicone#p973

viewtopic.php?f=50&t=4306&p=11353&hilit=safety+wire#p11353

 

[grumpyvette]

Re: studs or locking bolts for headers

[quote ]Hey GRUMPYVETTE?
I got the headers mounted, problem is there is always one header bolt that wants to go in crooked, as the holes in the header flange are not correctly located, maybe I have to drill the holes in the header flange a little bigger,[/quote]
Q: What causes an exhaust manifold stud/bolt to break?

A: The exhaust manifolds are formed from the factory using fine grain cast iron, and like most metals, it expands and contracts during duty cycles of heating and cooling. This expansion happens naturally, and at first, the manifold and mounting studs are in a state of “elastic deformation.” Elastic deformation is basically expansion and contraction over a period of time retaining the original size and shape. Each duty cycle will provide tension stress on the studs or bolts that hold the manifold in place. The mounting hardware exhibits flexibility over time. However, as the manifold continues to expand and contract more dimensionally, each consecutive time creates larger and larger tension forces that move beyond the elastic state of deformation and become what is referred to as “plastic deformation.” Basically the manifold stretches beyond return and fractures the mounting stud, leaving the manifold permanently deformed and dimensionally changed. This expansion and stretching of the manifold bolts over numerous duty cycles eventually causes too much tension on the bolt(s), stretching them beyond capacity and causing them to fail.

Information provided by: ProMaxx Tools

safety wiring bolts works
Safety wiring works equally well on nuts or bolts.

http://www.harborfreight.com/hand-tools ... 45341.html

I would point out that use of safety wired nuts and castle nuts with cotter pins, is in many applications, a separate,
and in my opinion better option ,
in that its both secure and easily removed if required, and less temp sensitive than chemical bonding agents.
yes obviously there are applications where loc-tite is the better option, and places where anti-seize and a castle nut and cotter pin or safety wire use is the best option.

http://garage.grumpysperformance.co...afety-wire-locking-fasteners.4306/#post-67524

http://garage.grumpysperformance.com/index.php?threads/cotter-pins.4733/#post-12852

read full caption

YES! its very common to find you need to drill out ALL the bolt holes a bit larger in the less expensive header brands , and even some of the high end brands at times ,simply because the heat of welding tends to warp the flange just a bit distorting the flange, its no big thing in most cases you simply find and use the next larger drill size and a quick clean-up pass thru each hole does the trick, youll also find that the use of studs or cap screw bolts, and copper header gaskets tends to make the job easier

this is an all to common issue because header manufacturers rarely check spark plug clearance with anything other than factory original cylinder heads for a listed application and even with factory original cylinder heads for a listed application, I occasionally see headers with what can only be described as PISS POOR CLEARANCE, for plugs , ignition wire and plug boots.

I would strongly suggest BOTH stainless bolts studs and the use of ANTI SEIZE on the threads

Report this image

the typical woven or aluminum foil reflective boot covers for protecting plug boots help but depending on the application they may not be adequate protection, it helps but over time heat still can burn thru the ignition wire insulation, the ceramic plug boots plus the shorter plugs and the heat resistant flex wire shields may be required on some headers to provide the required heat protection, and clearance, to the ignition wire

Report this image

use of shorter plugs helps in some applications,cutting a standard spark plug socket to a significantly shorter length and use of an open end of flex wrench eases access

BTW, its not really all that rare to find that the headers you have present a spark plug wire clearance issue,

SPACING THE HEADER FLANGE A BIT FURTHER AWAY FROM THE CYLINDER HEAD WITH A SPACER PLATE CAN AT TIMES BE HELPFUL

that makes installing the spark plug boots in such a way that they don,t contact the hot metal surfaces almost impossible , this can sometimes be helped a great deal by the addition of a header flange, or SPACER PLATE, that MATCHES YOUR PARTICULAR ENGINES CYLINDER HEAD EXHAUST PORT AND HEADERS,
if the exhaust header or manifold gaskets surface has not been damaged that should work, but if the gaskets damaged it will need to be replaced, thats one reason the soft copper gaskets are rather favored,
using anti-seize paste on bolt or stud threads helps prevent future problems
and failure to use anti-seize paste on any header or exhaust manifold bolt or stud will eventually cause problems ESPECIALLY if you use them on aluminum heads

What causes an exhaust manifold stud/bolt to break?

A: The exhaust manifolds are formed from the factory using fine grain cast iron, and like most metals, it expands and contracts during duty cycles of heating and cooling. This expansion happens naturally, and at first, the manifold and mounting studs are in a state of “elastic deformation.” Elastic deformation is basically expansion and contraction over a period of time retaining the original size and shape. Each duty cycle will provide tension stress on the studs or bolts that hold the manifold in place. The mounting hardware exhibits flexibility over time. However, as the manifold continues to expand and contract more dimensionally, each consecutive time creates larger and larger tension forces that move beyond the elastic state of deformation and become what is referred to as “plastic deformation.” Basically the manifold stretches beyond return and fractures the mounting stud, leaving the manifold permanently deformed and dimensionally changed. This expansion and stretching of the manifold bolts over numerous duty cycles eventually causes too much tension on the bolt(s), stretching them beyond capacity and causing them to fail.

Information provided by: ProMaxx Tools

thats significantly thicker being welded to the existing header flange , to space it out further away from the cylinder heads, obviously you don,t want to do this without testing all the clearances so installing the extra header flange with an exhaust gasket on both the cylinder head surface and between the header flange spacer and the existing headers as a test is strongly suggested as a test.
THIS IS ALSO USEFUL AT TIMES TO ADAPT THE ENGINE TO A DIFFERENT BOLT PATTERN OR SPACING
http://www.jegs.com/i/JEGS-Performance-Products/555/30790/10002/-1?parentProductId=977236

heres where you get spacer header flange plates

http://www.jegs.com/p/JEGS-Performance-Products/JEGS-Header-Exhaust-Flanges/1127498/10002/-1

http://www.summitracing.com/search/Part-Type/Header-Flanges/

http://www.hedmanhusler.com/Hedder-Flanges-without-Stubs

http://rehermorrison.com/product/adapter-plates/

 

[DorianL]

Why do you prefer copper? Are they less prone to leakage?

 

[LEJ ZO6]

I tried all kinds of exhaust header gaskets when I raced the C3 with SCCA.

Spent a lot of money on gaskets because we removed the exhaust frequently.

Finally an old racer told me to try the new high temperature silicone sealant between the header and the head and I wouldn't need to buy gaskets any more. I tried it. It worked great. I never bought exhaust header gaskets again.

I'm not sure how long this would last on a street car but it would last several weekends at the track before the headers had to be removed again.

 

[grumpyvette]

Re: studs or locking bolts for headers

I got an email,

" GRUMPY, I was replacing my header gaskets and the bolt holding the dip stick bracket to the head sheared off when I tried to remove it, any ideas?"

http://garage.grumpysperformance.com/index.php?threads/what-header-gaskets.3107/#post-8291

http://garage.grumpysperformance.com/index.php?threads/header-bolts.559/

busting off or cross threading a bolt is a common problem, that takes time, experience and a few cheap tools to fix, but obviously you need to know how to proceed, these links will help
if you can get access with a drill , at the correct angle to drill out the bolt center line ,once the headers been removed, you can use a penetrating solvent/ lubricant spray to loosen the threads , and repeated heat and cooling cycles and an easy out reverse twist drill to remove the broken bolt.
if you can,t get access you might need to remove the intake and head to do the repair so keep that in mind, as an option rather than getting lazy and butchering the job if you can,t get access,(which Ive seen many guys do in the past) because its likely to become a much bigger, and more expensive repair issue if you screw up the repair, trying to avoid doing it correctly, by removing the head if thats the only way to get access

BOB, if you need help give me a call, I,ll be free later today

these links will help
http://forum.grumpysperformance.com/viewtopic.php?f=59&t=807&p=18280&hilit=bolt+rusted#p18280

http://forum.grumpysperformance.com/viewtopic.php?f=50&t=173&p=207&hilit=+bolts+grade#p207

http://forum.grumpysperformance.com/viewtopic.php?f=50&t=837&p=1264&hilit=taps#p1264

http://forum.grumpysperformance.com/viewtopic.php?f=59&t=1264&p=6141&hilit=taps#p6141

http://forum.grumpysperformance.com/viewtopic.php?f=50&t=4868&p=13372&hilit=bolts+grade#p13372

 

[Grumpy]

hey grumpyvette!

I have a neighbor that insisted that aluminum header gaskets work better than,
the copper ones you suggest or the multi layer paper type the auto parts store sells, so any input here??

your not the first and you certainly won,t be the last person to ask a similar question, so lets look at the basic physics and material property's of each material, maybe its my engineering back ground, but I have always looked at the materials used their basic strength and hardness, flexibility, heat tolerance and solvent resistance properties before just grabbing and installing a part some guy in the auto parts store suggested I use!
your header gaskets will be compressed between the cylinder head and the header flange,if they are compressed between the two surfaces without any leaks , almost any gasket will work for awhile,all the gasket materials work if the clamp force is consistent and theres no surface flaws.

keep in mind the temps, listed in the chart, above are on the lower end of the range and under ideal running conditions, its fairly common for a performance engine with high compression to have exhaust gases exiting the exhaust ports to fall in this range 752°-1112°F "BTW RG is Regular Gas"

but its blocking a high pressure pulse of rather hot gas that can under some conditions exceed 1000 plus degrees F , its purpose is to fill the irregularities in the surfaces,and the basic physical property's, obviously if you subject a gasket to temperatures or pressures that exceed it strength potential failure is eventually a potential issue.
between the two,where the two components mate as there are usually some minor inconsistency's and the gaskets are designed to prevent leaks as they make a rather annoying noise and can present a health issue in that you can,t breath the exhaust gasses in any significant percentage in the air in the cars passenger area, without getting sick or worse.
I'm sure you've heard of guys falling asleep with the car idling in the garage and the carbon monoxide eventually proving fatal.

laminated compressed layered headers gaskets like these eventually cook into a carbon like charcoal consistency , especially if theres an inconsistent mating surface that allows micro leaks

its fairly common for a performance engine with high compression to have exhaust gases exiting the exhaust ports to fall in this range 752°-1112°F
that will cook or carbonize or melt either paper or aluminum header gaskets if theres even a slight leak or you run a bit lean or retarded which both result in increased exhaust temp ranges
The compression of the gas by the piston in the cylinder causes the gas temperature to rise and this temperature rise increases with increasing compression ratio. Since the compressed gas is a mixture of air with a volatile fuel, it may ignite spontaneously without a spark when the volatile fuel reaches its flash point before the piston has reached top of the compression stroke. This effect is called pre-ignition and limits the maximum compression ratio of a spark ignition engine to about 12:1

Compression ratios of spark ignition engines are typically in the range from 8:1 to 12:1
both cylinder pressure and exhaust gas temperature increase as the compression (increased thermal efficiency) and
engine rpms increase (number of exhaust pulse volume exiting the ports increase) at 8000rpm theres 67 exhaust pulses PER SECOND, and reach 1000F plus

http://www.engineeringtoolbox.com/melting-temperature-metals-d_860.html

Metal Melting Point
(oC) (oF)
Admiralty Brass 900 - 940 1650 - 1720
Aluminum 660 1220
Aluminum Alloy 463 - 671 865 - 1240
Aluminum Bronze 1027 - 1038 1881 - 1900
Antimony 630 1170
Babbitt 249 480
Beryllium 1285 2345
Beryllium Copper 865 - 955 1587 - 1750
Bismuth 271.4 520.5
Brass, Red 1000 1832
Brass, Yellow 930 1710
Cadmium 321 610
Chromium 1860 3380
Cobalt 1495 2723
Copper 1084 1983
Cupronickel 1170 - 1240 2140 - 2260
Gold, 24K Pure 1063 1945
Hastelloy C 1320 - 1350 2410 - 2460
Inconel 1390 - 1425 2540 - 2600
Incoloy 1390 - 1425 2540 - 2600
Iridium 2450 4440
Iron, Wrought 1482 - 1593 2700 - 2900
Iron, Gray Cast 1127 - 1204 2060 - 2200
Iron, Ductile 1149 2100
Lead 327.5 621
Magnesium 650 1200
Magnesium Alloy 349 - 649 660 - 1200
Manganese 1244 2271
Manganese bronze 865 - 890 1590 - 1630
Mercury -38.86 -37.95
Molybdenum 2620 4750
Monel 1300 - 1350 2370 - 2460
Nickel 1453 2647
Niobium (Columbium) 2470 4473
Osmium 3025 5477
Palladium 1555 2831
Phosphorus 44 111
Platinum 1770 3220
Plutonium 640 1180
Potassium 63.3 146
Red Brass 990 - 1025 1810 - 1880
Rhenium 3186 5767
Rhodium 1965 3569
Ruthenium 2482 4500
Selenium 217 423
Silicon 1411 2572
Silver, Coin 879 1615
Silver, Pure 961 1761
Silver, Sterling 893 1640
Sodium 97.83 208
Steel, Carbon 1425 - 1540 2600 - 2800
Steel, Stainless 1510 2750
Tantalum 2980 5400
Thorium 1750 3180
Tin 232 449.4
Titanium 1670 3040
Tungsten 3400 6150
Uranium 1132 2070
Vanadium 1900 3450
Yellow Brass 905 - 932 1660 - 1710
Zinc 419.5 787
Zirconium 1854 3369

 

[87vette81big]

This is a sore spot for Pontiac V8 guys with long tube headers Grumpy.
The main culprit I have found is that the Factory motor mounts are Constantly taking a Severe Beating Everytime you hit the Gas WOT.
The Headers move with the Rocking engine and rest of exhaust system.
Fabbed Solid Motor Mounts work best.
Can't just go to Summit Racing and buy solid motor mounts for a Pontiac V8.
Won't find them.

 

[87vette81big]

REMFLEX Graphite Header gaskets are getting popular now.
They are made for Pontiac V8 D-Port.
And for Pontiac Ram Air IV.
I may buy a set of ROL Header gaskets and try them out.

Also made for Big Block Olds V8.
All stocked at my local Hotrod Speed Shop.

Real thick Graphite gaskets.
About 3/16" thick uncompressed uninstalled .

 

[87vette81big]

 

[chromebumpers]

I just noticed an open gap in the back end of my headers on my sbc. Can I just tighten all the bolts down and expect that will be good enough, just install new gaskets or must I pull things apart and see what the gaskets looks like first. Even though I didn't install these headers I know there's not many miles, perhaps just a few hundred miles since installed.