Head Bolts!!

**pmolina0436** · 03-25-2009, 08:12 AM

what kind of head bolts are used in an 04 GTO??

1st design (2 bolts size 100mm and 155mm)

2nd design (1 bolt size 100mm)

http://www.autozone.com/autozone/cat...entId=cat10008

**6.0LiterImportEater** · 03-25-2009, 05:57 PM

Why do you need new headbolts?

Did you put on new heads or port/polish....any engine upgrades?

If you have I would HIGHLY RECOMMEND ARP Headbolts! Nothing but the best!

If you have it apart you can always measure the length.

**qwkgto** · 03-25-2009, 11:36 PM

I agree get ARP can reuse them and way stronger then those TTY that GM uses.

**0rion** · 03-27-2009, 08:21 AM

I think he's asking what size. I'm *pretty* sure the goats have just 1 size and not 2 like the earlier LS1's. Hopefully someone that's actually pulled the heads on an 04 will chime in.

**mark21742** · 03-31-2009, 03:18 AM

Originally Posted by 0rion

I think he's asking what size. I'm *pretty* sure the goats have just 1 size and not 2 like the earlier LS1's. Hopefully someone that's actually pulled the heads on an 04 will chime in.

money was tight when I did mine so I ordered both sets from Autozone TTY bolts. mine was the old style(03 motor), but still used the new stlye bolts (all the same length) right at $30 per head for the bolts

**pmolina0436** · 03-31-2009, 07:47 PM

Originally Posted by 0rion

I think he's asking what size. I'm *pretty* sure the goats have just 1 size and not 2 like the earlier LS1's. Hopefully someone that's actually pulled the heads on an 04 will chime in.

yea they were all the same size..

**GTO1_OHIO** · 03-31-2009, 07:48 PM

Mine had two different sizes.

**0rion** · 04-01-2009, 03:11 AM

Originally Posted by pmolina0436

yea they were all the same size..

Originally Posted by GTO1_OHIO

Mine had two different sizes.

what are the build dates on your cars? Wonder if there's any way to know what bolts you have prior to tearing it apart.

**mark21742** · 04-01-2009, 03:52 AM

Originally Posted by 0rion

what are the build dates on your cars? Wonder if there's any way to know what bolts you have prior to tearing it apart.

07/03 (car) 04/03 engine build date here

**GTO1_OHIO** · 04-01-2009, 03:58 AM

Originally Posted by 0rion

what are the build dates on your cars? Wonder if there's any way to know what bolts you have prior to tearing it apart.

The car is 12/03, don't where to look for the engine build date.

This is what I've found, mid-'04 GM switched from using 16 long (155mm) bolt and 4 short (100mm) bolts to 20 short ones.

ARP part number(s) for the "long" and the "short" set up:

134-3609 Long
134-3610 Short

**Yellow GTO** · 04-01-2009, 04:27 AM

My car was made april 04 all the same length.

**GTO1_OHIO** · 04-01-2009, 04:37 AM

Originally Posted by mark21742

07/03 (car) 04/03 engine build date here

????? Production didn't start on the GTO until September 9 2003.

Originally Posted by Yellow GTO

My car was made april 04 all the same length.

That would be the 8th month of production.

**qwkgto** · 04-01-2009, 05:32 AM

Oh bullpucky, does it say 2004 on your title?then its a 04 ,mine says april 05 its a 05

I think all the newer block 2004 and up have the same lenght bolts older ones its game of chance they changed the ls1 so many times only way to know is pull a few bolts out,hope you have the same lenght ones as the mismatched ones are alot ,are expensive.

**pmolina0436** · 04-01-2009, 07:01 AM

Originally Posted by qwkgto

Oh bullpucky, does it say 2004 on your title?then its a 04 ,mine says april 05 its a 05

I think all the newer block 2004 and up have the same lenght bolts older ones its game of chance they changed the ls1 so many times only way to know is pull a few bolts out,hope you have the same lenght ones as the mismatched ones are alot ,are expensive.

true

**mark21742** · 04-01-2009, 10:44 AM

Originally Posted by GTO1_OHIO

????? Production didn't start on the GTO until September 9 2003.

That would be the 8th month of production.

crap, i was a year off on the car's build date, the car was built 07/04 i guess i shouldn't try to remember too many numbers when i'm two states away from my car and can't check to verify lol