turbotuner20v

I'm looking at different motor options and I'm curious to know more about the '6-bolt' setup (like what you would get with an LSX block)

It sounds like it uses more head stud holes? So they also use 6-bolt specific heads? I assume there has to be GMPP 6-bolt heads as well as aftermarket since the LSX 376 block seems to use LS3 heads w/ 6-bolt holes?

If there are pics to compare the differences, that'd be nice to see as well.

TRINIC5

Its simple, the standard motor both heads and block has 4 bolts per cylinder to hold the heads down, now some guys buy the 6 bolts heads but only use 4 bolts because their block don't have the accomadation for 6 bolts but with a highly boosted motor a 6 bolts system are recomended, meaning 6 bolts per cylinder.
The LSX, Warhauk and RSH blocks do accomadate the 6 bolts and yes GM Performance has a 6 bolts heads but I also understand its very difficult to get because of it not manufacturing fast enough.
I recomend the RHS 6 Bolts block and the 6 Bolts Black Label Heads as the best for high boosted motor, its also lighter than the LSX and in some cases its also stronger.
An Iron block gets hotter with boost and keeps the heat longer. Maybe talking to an Engine builder will help you know the differences.

turbotuner20v

Are the 4 bolt holes running along the top and bottom of the cylinders the holes that complete the '6-bolt' setup?

Unreal

Yes, you need a 6 bolt block, 6 bolt heads, 6 bolt head gaskets, and 6 bolt headstud kit.

See the 2 extra holes in the middle of each bore?

turbotuner20v

cool, figured it was pretty straight forward, but just wanted to verify what I was looking at.


So I guess GM would use their basic headbolts and their own gmpp head gasket for their lsx376 motor? I wonder how many layers it is or how it compares to an LS9 gasket.

Unreal

3 layers and ~.045" I believe.

turbotuner20v

Would a 6-bolt motor with head bolts and 3 layer gasket still be stronger than a 4-bolt motor with head studs and ls9 gasket? (assuming iron block for both)

Unreal

I don't know if anyone makes head bolts for the 6 bolt blocks. The ARP stud kit is all I saw and it is $440. I would say very much yes.

turbotuner20v

Would the GM lsx376 use arp studs then? I figured they would use a cheaper option.

turbotuner20v

It looks like the lsx376 uses 4 bolt heads on the lsx block, so I guess it would just use the normal bolts.

Bigwebb

so no issues running a six bolt head on a 4 bolt stock ls3 block? Looking to build a 520ish whp NA setup.

BigBlue

I'd think a set of ported and milled stock heads would be fine for 520ish.

Unreal

Zero issues.

stevieturbo

Any reason you'd choose 6 bolt heads for such a build in the first place ?

Any block/head combo would be perfectly safe for that sort of build.

xBoostx

I have 6 bolt heads on my heads and cam ls3 few reasons for it first about same price second they are actually made stronger by the existence of the outer bolt additional aluminum, will allow room to grow in case later wanna go fi and better resale value.

silver408z

Do NOT us 4 bolt gaskets on a 6 bolt setup. When you start torqueing stuff down, you will break off the tabs. I know that was not what you were asking but it is something to make sure to do right.