b00sted

iTrader: (7)

I ordered a set of arp head bolts for an LS1, but they're the wrong size for this motor. It's got an afr head, and the bore is a standard ls1 bore. Is the head bolt for an 04 gto motor somehow different than every other ls1 or something? Also, the thermostat I got(for an ls1) is the wrong size too.

Now I think the water pump assembly could be off of an ls2(which is why the thermostat is different), but I can't figure out why the head bolts won't fit.

Any ideas?

MESS

iTrader: (5)

that sucks bro, sounds like your either getting the wrong parts or someone is playing a trick on you.....

RedLT4Mike

iTrader: (4)

I think there are 2 pn's for head bolts.
Ls1's w ls1 block
and
ls1's w/ ls6 block.

don't quote me on that, but I think I heard
that before.

b00sted

iTrader: (7)

Well ARP says the bolts will work on an ls1 or ls6.

I'm thinking I'm gonna need to get the ls2 bolts and try them.

b00sted

iTrader: (7)

I just looked and ARP has a part # for the ls1/ls6, and then a seperate part # for the 2004 motors. That's where my problem was.

Thanks for the help guys.

Marc 85Z28

iTrader: (8)

GM changed the design for the later LS1s. Older LS1s had 8 long and 2 short head bolts, while you should have 10 short or all equal length bolts.

Rob

iTrader: (6)

After Jan. '04, the head bolts changed. As well as the water pump, among others, to help the change over to LS2.

LS1 in GTO is an LS6 block.