1CAMWNDR

iTrader: (21)

What is different about head bolts on the 2004 and newer models vs. the 1998-2003? The reason I ask is that Thunder Racing has ARP head bolts for the 1998-2003 cars at $147. The 2004 and newer head bolts are only $96 .
Here is the page:
http://www.thunderracing.com/catalog...vid=3&pcid=157

radkon

iTrader: (2)

I remember there being two different sizes. Got us GTO owners doing head swaps as some had the longer bolts and some had shorter bolts. Lemme see what I can dig up.

Here is some info:
http://www.ls1gto.com/forums/showthr...d+bolts+length

http://www.ls1gto.com/forums/showthr...d+bolts+length

http://www.ls1gto.com/forums/showthr...d+bolts+length

KCFormula

iTrader: (4)

Yes they headbolts got shorter threads inside the block. The previous headbolts will not fit in a '04 block.

1CAMWNDR

iTrader: (21)

I see. Thank you for the info.

Rob

iTrader: (6)

Yep, on my GTO, the bolts were all the same size.

Ray South

iTrader: (1)

The heads are identical, the block is what has changed. Instead of 3 different sized head bolts, there are only two different sizes. The high compression area around the cylinders uses the same length bolts for all 10. The intake area of the head, uses the standard 10mm bolts that has been used previously.

When purchasing the ARP head bolt systems they will only cost you approx. 100 instead of the customary 139 on most web sites.

There are several other changes that were made, I believe, in an effort to begin the tooling process for the LS2's. Different types of electrical connectors were put on O2 sensors just to name one.

Ray