'04 blocks Dont necessarily take the standard LS1 ARP head studs. Thanks to East Side Performance , we found out that at least some of the '04 blocks need 20 short studs, wher the 97-03 use 16 long and 4 short. So, if you have a new block, ARP is not currently shipping head studs for you!

 

ARP does have head studs for the '04+ blocks. Not sure on the part #, but I have used them on a few motors so far.

 

Dammit... I guess not all the sponsers are aware of that..Let this be a note for their salesmen.

 

any particular reason GM made the thread lengths different?

 

just to **** with me i think

 

Cheaper bolts.

 

Yep, same with the iron blocks

 

I had asked this ? a month or two ago....I have a 04 ls6 block.....here I go all 03 mid year and 04 ls6 blocks have the medium length m-11 bolts used to torque the heads down and the short m-8's at the top. Ls2 blocks have this same arangement. Same block design...and the differece between the ls1 and ls6 thread depths was to allow for room in the block for the windows...in the ls6 block. So if you go with factory head bolts.....get them for a Ls2 the part numbers for the ls6 03-04 and Ls2 are the same....and when I bought them you have to order alll the m-11 and m-8 bolts seperately. No head bolt kits like the Ls1.....as of yet. Also the head bolt torqueing is different.....there is a post on here that had answered this? Just search for it....I believe under head bolt torqueing for a ls6

 

I think you are both right.