Remy_

I have a 2003 50th anniversary Z06 and I don't know what head bolts I need to buy can anyone help me out?

leadfoot4

If I were you, I'd check with the ARP catalog.....

schmuckingham

Le Search Results


Like Leadfoot said, I would go ARP.

feeder82

Like above can't go wrong with ARP. The factory fasteners are not reusable.

Remy_

Im just confused as to what exactly I should get from ARP

schmuckingham

I would just use the regular ARP head bolts. Kit 134-3609 will do the trick as long as the engine in your car is still a '03 engine.


Unless you are doing some upgrades then you would want to look into the appropriate head studs.

grinder11

Get whatever ARP recommends. Nobody here knows as much about ARP fasteners as ARP themselves!

hungryhippo

There was a change in head bolt lengths around 2003. Only way to know for sure is to remove the old ones.

Prop Joe

FWIW
When I installed 2003 CNC ported 243 heads on my 1998 car, I was told the head bolts/studs are block specific.
I put studs in mine (overkill) as I had a few OEM bolts come out with mucho running torque, even once they were broken free. These guys had them in stock and fit perfectly:
Winners Circle

Take a whizz wheel or dremel tool to cut slots in the threads to collect debris while running the bolts in and out to clean the aluminum threads in the block. clean and re-clean.

Crude but effective. compliments of LS1howto.com

93Polo

'03 is most likely the standard early LS1 lenght but might be LS2 style. Only 1 way to know for sure as the casting number is the same.

https://ls1tech.com/forums/generatio...lt-length.html

Bill Curlee

Once you determine the proper head bolt design for your engine, here are some VERY HARD LIVED/LEARNED FACTS about LS Engine head bolt installation that I have learned over the years of LS engine modding/repair:

1. The bolt holes for ALL the head bolts in all LS blocks are blind holes. IF, there is water/coolant/dirt debris in any of the holes when you torque the bolts, it will rupture the block or cause inaccurate torque readings! CHECK AND DOUBLE CHECK the holes for being clean and dry conditions. You cant compress liquid!
2. I very strongly recommend using ARP head studs! YES,, Its over kill but I have personally seen three people using the normal Torque To Yield (TTY) Bolts and pull the threads right out of the block!. YES they were using a proper high quality, and properly working torque wrench. I WILL NOT, work on anyone's LS engine head install without using studs.
3. YES, They will allow you to install the head with the engine in the car without any fitment/interference issues. I have ARP Head Studs in my 02 ZO6.
4. If you use OEM Style TTY BOLTS, at least use the ARP bolts.
5. If the bolts do not easily thread into the head all the way in up to the top of the head surface without much resistance, I would recheck the hole for being properly dry and clean.
6. If you decide to spring for the head studs, please don't cheep out and get some off shore ARP knock off studs. I know some one that did and one of the studs failed. At least the stud broke and it didn't damage the block.

Things that I have learned cleaning out LS Block bolt holes:

1. Blowing compressed air into the hole with an everyday chuck wont blow out all the coolant/water/dirt! Trust Me. I've tried!
2. DO NOT use a Thread Tap in the holes!! Use Prop Joe recommendation for making a tool from an old throwaway bolt or purchase a dedicated correct size thread cleaning tool..
3. I have an air blow tool with a long aluminum tube that fits into the block hole all the way to the bottom of the hole. Even after blowing the hole out, using that tool I use long cleaning Q Tips to swab into the hole to make sure the hole/s are dry.

LOL,, ALL OF THIS for a simple head bolt install and torque. YEP! When you are pulling that torque wrench handle and waiting for the "click" and it just keeps turning, it REALLY REALLY SUCKS!!! Hey,,, The Keen Sert thread repair set is available if TTY fails. Its very pricy but works! LOL! Brother, I've seen the anguish! It isn't pretty..

Bill

romandian

the tool is called thread chaser. its basically a tap without cutting rake ("hook").

schmuckingham

Also an alternative to what the others have said about cleaning the threads. I used this when I did my heads and head studs with great success, but it is not a one pass and done thing. Takes multiples passes and some air to great them squeaky clean.

Bill Curlee

When cleaning block head bolt holes, you will want to have the following:

1Cleaning tap or home made cleaning bolt
2. Brake Parts Cleaner with the little red nozzle hose
3 Plenty of long wooden Q Tips
4. A nice bright flash light
5. An air chuck that has a long metal wand that will fit into the bolt hole and go to the bottom of the hole.

BC

sonicss33

And don’t forget to wear your safety glasses when blowing out the holes.

leadfoot4

With respect to cleaning out the bolt holes, while the holes most certainly need to be 100% clean, you also need to be careful not to distribute any debris into the engine, which could occur when using compressed air in the holes. My suggestion, if you have a shop vac, is to put together a contraption like I did, in order to get suction into small areas. It the "reducer cone" attachment, that comes with many of the vacs, with a piece of Tygon hose "gorilla taped" to the inlet ......