[Abs]

The bolts are M8-1.25 × 25mm, flange head, 10.8 hardness. Shocked that I got a pair at the local Tractor Supply.

Rich,

I saw your For Sale post for this dampener. When was the build date on your 04?

Mine is May. Wonder what my spacing will be. If it does have the holes for the ls2 dampener, it might also mean it has an LS2 timing chain.

Back in the day, when Svede's 04 GTO's engine failed and his chain snapped due to a failed lifter, he said it actually had an ls2 timing chain. Here's a link to that thread:

https://www.gtoforum.com/posts/439402/

I can't find another report of an ls1 GTO with an ls2 timing chain though. People probably don't pay much attention to the old chains when they swap them.

 

[Abs]

you probably don't have the LS2 chain. i know mine didn't.

even if you do, replace it.

check this out. This is more for reference than me thinking I'll reuse mine if I have it off because I am swapping oil pumps.

wow my 04 ls1 came with ls2 chain and drilled for ls2 tensioner - CorvetteForum - Chevrolet Corvette Forum Discussion

I think you actually had the ls2 chain and didn't realize it.

Something else I didn't know. From 02 onward, all ls1s used the ls6 block. I think the only difference was venting between cylinders under the valley cover. But still, all 04 GTOs have an ls6 block, and some (not sure what %) even had ls2 timing chains.

 

[Abs]

no i didn't.

But the ls2 dampener fits it? 🤔