97badass

iTrader: (8)

pretty sure its an lq4 it has slightly dished pistons. i would like to have around 10.5 i am wanting to get around 450-500 rwhp n/a 600+ on spray

MattSapp95_T/A

iTrader: (35)

If they torque the rods down in a rod vice and the big ends are out they can't pull the caps and shave the flats and re hone like the old SBC rods since these are cracked caps...

So what they do is punch them out .002 and they make a special bearing for the LS crack cap rods that makes up for it....

this is very common when switching to ARP hardware and changing the clamping load and distorting the big end...


Yes the LQ4 is dished.... the LQ9 has flat pistons...

What CC chamber are the heads you are using...
These motors come with a -.005 piston compression height (piston is out of the bore a little) and you wanna keep your quench in the ~40s so if you can tell me what cc head you have I can tell you what you compression will be...

Stock LQ4 is 9.4:1 I believe with a 6cc dish

97badass

iTrader: (8)

ls3 heads milled .030

97badass

iTrader: (8)

if i switch to arp rod bolts is it mandatory to have them punched out the .002 your talking about? or can i just use stock bearings?

93Z2871805

iTrader: (5)

You'd have the machine shop install the bolts and check for distortion, re-size if needed.

The LS2 rods look WAY beefier compared to the LQ4 rods and have floating pins.

Milling .030 of the heads should give you around 10.6:1 CR

LS2 rods/pistons are about 125-250 for a set and yield 10.9:1.

MattSapp95_T/A

iTrader: (35)

Before I fell and hit my head and I was gonna use LS2 rods I put ARP bolts in them and had my machine shop check them and they were fine and didn't need to be touched...

As for your compression
4.000 bore
.051 crush head gasket
-.005 deck height
3.662 stroke
decking .030 puts you at ~65 cc
LQ4 pistons have a ~7 cc dish

So your compression with the LQ4 pistons would be - ~10.2

or 11.09 with LQ9 Flat tops

Also all the floating pin rods are the same as the LS2 rods and are stronger than the pressed rods

93Z2871805

iTrader: (5)

Yeah, what he said^

Actually 6.7cc piston, 64cc when milled .030, coming out to 10.37:1.....but that's splitting hairs, lol.

97badass

iTrader: (8)

if i use the ls2 rods and pistons but dont mill the heads will the pistons need flycut?

97badass

iTrader: (8)

goind from the stock 317 heads to stock ls1 heads would be a downgrade right? i can pick up some 317s for $50 that has the exhaust bolts broken off...

MattSapp95_T/A

iTrader: (35)

I just put 7 to make things more simple... .3 won't matter much
As for the 64cc there is no way to know for sure what his Head CC will be without him having them checked at the machine shop since these heads vary a lot from the factory...from 68-71

but I am picking up what your puttin down kenny.....


Depends on cam selections... With my 230/242 600/605 cam I had not PTV issues and did not flycut....

never really looked into it but I would rock the 317s on the 6.0 then when you get ready throw the ls3s on it

93Z2871805

iTrader: (5)

I'd go for 5.3 heads if you want to go cathedral, then you could run the lq4 pistons and keep compression up.

97badass

iTrader: (8)

wont be going cathedral, waste of time/money if im going to go ls3 later on. right now the build is on hold till i sell the lt1 stuff... i bought that stuff then a week later bought the lq4 i juet couldnt resist it. more power cheaper.

97badass

iTrader: (8)

whats some of the smaller/cheaper things to get? i will order the brackets from summit, wiring harness and ecm and get the harness sent to merv

93Z2871805

iTrader: (5)

Gaskets, rings, lifters, offset rockers.

97badass

iTrader: (8)

do all 16 need to be offset? or just the exhaust? i have the rockers and mounts for an ls1 will that work? just get offset rockers...

the_merv

iTrader: (88)

To run the L92/LS3 Heads you need 8 Offset Rockers..they are for the Intake, and the L92/LS3 Rocker Pedistals.

97badass

iTrader: (8)

ok thanks merv, whats the difference in the pedestals?

the_merv

iTrader: (88)

They are spaced differently.

93Z2871805

iTrader: (5)

^^You are correct sir.

97badass

iTrader: (8)

thank you guys for all the help so far!