NitrousJunkie

iTrader: (5)

Whats a good amount to have a stock set of LQ9's milled to help gain a some compression on an Ls1? Thanks.

Chris

Hugger

iTrader: (21)

Mine are milled .030" which I am told puts them back at stock compression.

Y2kforgedSS

Lets say i want to mill my heads, if im thinking right this can boost up compression right? Well if so whats the farthest i can mill my heads to get my compression up.

JZ'sTA

iTrader: (23)

It depends on what compression your after and what head your starting with.
As far as the 6.0 head. If you doing a set of 6.0's you loosing compression if they aren't milled.
You will need to mill them around 27 thousands (guick math in head, but I am sure that is pretty close) to get them back to stock compression using a .054 gasket.
If you want to run 11:1 I would suggest a different head.
The 5.3 head or LS6 head would work much better for this.
It would take about 60 thousands of milling to get to 11:1 using the 6.0 heads and a .045 gasket.
That is a bunch. Now there is also something called angle milling. Not as popular but very effective. You dont loose as much P/V clearence when angle milling. I dont know exactly how it works but it works.
Do some searching as I and many others have covered the compression issue many of times, and you can find tons of info.

Y2kforgedSS

hey thanks jzsta but you more or less covered what im looking for. I have the 5.3 stage 2 heads but was hoping maybe to get them milled, ported and polished just a bit more. do you think that i can get more out of the heads i have?

JZ'sTA

iTrader: (23)

Much more power can be gained. TEA would be my choice but ET performance and PRC seem to do some nice heads as well.
You wout need much milled as you will be 11:1+ with a good head gasket choice. While they are being CnC ported they will clean the heads up which is normally a 2-5 thousands mill. Now run a .045 gasket and your set.
If you wanted more then 11:1 just tell whoever you decide to port them and go from there.
For around 1000-1200 dollars you can have a set of killer 5.3 heads. (that price is because you already have the cores) Good luck with what you decide, and if you need some more help or info my PM box is open.

Y2kforgedSS

Hey thanx for the help man, you answered all of my questions without leaving me wondering.

ArcticZ28

iTrader: (14)

Just do what I'm doing, junk the engine and get a 408 with flat top pistons and you'll be right at 11:1 with the stock LQ9 heads

JZ'sTA

iTrader: (23)

HAHA, very true. That added stroke really makes a difference, and the added bore adds a bit more compression as well.