2004 Head Bolts
Thread Starter
Melting Slicks
Joined: Nov 2005
Posts: 3,323
Likes: 142
From: Green Valley Arizona
2004 Head Bolts
Do all '04s LS1 heads use the same length M11 bolts and then five M8 bolts?
Looking at ARP head bolts and the kit for a '04 does not list the 5.7L engine; has 5.3, 6.0.
Other than removing the head bolts, is there a way to determine if the M11 bolts are all the same length?
Trying to have all parts before I begin the tear down.
Thanks
Looking at ARP head bolts and the kit for a '04 does not list the 5.7L engine; has 5.3, 6.0.
Other than removing the head bolts, is there a way to determine if the M11 bolts are all the same length?
Trying to have all parts before I begin the tear down.
Thanks
Tech Contributor
Joined: Jan 2007
Posts: 19,398
Likes: 1,139
From: Dyer, IN
Do all '04s LS1 heads use the same length M11 bolts and then five M8 bolts?
Looking at ARP head bolts and the kit for a '04 does not list the 5.7L engine; has 5.3, 6.0.
Other than removing the head bolts, is there a way to determine if the M11 bolts are all the same length?
Trying to have all parts before I begin the tear down.
Thanks
Looking at ARP head bolts and the kit for a '04 does not list the 5.7L engine; has 5.3, 6.0.
Other than removing the head bolts, is there a way to determine if the M11 bolts are all the same length?
Trying to have all parts before I begin the tear down.
Thanks
Thread Starter
Melting Slicks
Joined: Nov 2005
Posts: 3,323
Likes: 142
From: Green Valley Arizona
Yep, that is one of the two ARP bolt kits I was looking at. Clicking further on the ARP website is where they listed engines and the 5.7 was not there.
Kit ARP-3601 is the other kit. But it has the two different length M11 bolts and shows 2003 as the last year, but does list the 5.7.
I am going with the 3610 kit and hope I do not have to return it.
Thanks.
Kit ARP-3601 is the other kit. But it has the two different length M11 bolts and shows 2003 as the last year, but does list the 5.7.
I am going with the 3610 kit and hope I do not have to return it.
Thanks.
Tech Contributor
Joined: Jan 2007
Posts: 19,398
Likes: 1,139
From: Dyer, IN
Yep, that is one of the two ARP bolt kits I was looking at. Clicking further on the ARP website is where they listed engines and the 5.7 was not there.
Kit ARP-3601 is the other kit. But it has the two different length M11 bolts and shows 2003 as the last year, but does list the 5.7.
I am going with the 3610 kit and hope I do not have to return it.
Thanks.
Kit ARP-3601 is the other kit. But it has the two different length M11 bolts and shows 2003 as the last year, but does list the 5.7.
I am going with the 3610 kit and hope I do not have to return it.
Thanks.
Thread Starter
Melting Slicks
Joined: Nov 2005
Posts: 3,323
Likes: 142
From: Green Valley Arizona
@lucky131969 you have a valid point.....I am not in a hurry. In fact, it turns out that I am going to have to wait until I have the timing cover off to order a timing chain dampener as I need to measure the distance between bolt holes to get the correct one, so I will be waiting.
And no I have not contacted ARP or Summit, but have read more and appears that the M11 bolts are all the same length. But I am going to wait until I get the heads off.
Thanks for the replies and the reality wake-up.
And no I have not contacted ARP or Summit, but have read more and appears that the M11 bolts are all the same length. But I am going to wait until I get the heads off.
Thanks for the replies and the reality wake-up.
Team Owner
Joined: Oct 1999
Posts: 31,976
Likes: 487
From: Guinness Its whats for B'fast JAWGA
CI 3-4-5-9 Veteran
I have asked about this in the past and tried to research it. My understanding is there is no way to know on a LS6 block if it is the early or late head bolt design.
The change appears to be made as part of the final machining of the block and there are no casting differences, in casting number, flashing lines, etc.
Thus, you have to pull the head bolts out to verify which you have, unless of course you know that the car the block came out of is pre 04 or a later 5.7 CTS-V.
On the upside some of the later LS6 blocks were drilled for the LS3 pattern timing chain damper. I don't know if the 04 Corvette had it but later CTS-Vs did.
The change appears to be made as part of the final machining of the block and there are no casting differences, in casting number, flashing lines, etc.
Thus, you have to pull the head bolts out to verify which you have, unless of course you know that the car the block came out of is pre 04 or a later 5.7 CTS-V.
On the upside some of the later LS6 blocks were drilled for the LS3 pattern timing chain damper. I don't know if the 04 Corvette had it but later CTS-Vs did.
Last edited by 93Polo; Mar 29, 2025 at 01:36 PM.
