boosteds10

Anybody know the specs one the stock 5.3 and 6.0 heads? Like intake and exhaust runner volumes, combustion chamber sizes, and flow numbers.

chrisfrost

iTrader: (8)

Hello , how's it going ? All Ya gotta do is Google "GM # 12561706 or 12561862" or "1999-2004 chevy 5.3L cyl heads specs" . I'd rather teach You how to fish than ...... Good luck Any questions other than basic specs or if You can't find something ........ask by all means . Oh Ya , did You see the sticky at the top of this section , it's also got all that info , thanx

boosteds10

Well my reason behind asking this is, I will soon be doing a turbo 5.3 for my street s10 and was wondering which head would be the best for it.
I know the 317s lower the compression and flow comparable to the z06 heads but do I really need that? I've been told that lowering the compression like that for no more boost or power than I want to make, will make it a sluggish pig off boost.

Any input would be greatly appreciated!

chrisfrost

iTrader: (8)

I can tell You this , any boosted application will blow up with moderately high compression ratio , I'm not sure what the exact #'s are but in general between 8 and 9 to 1 is about the most You want to go . But I don't really know all that much about turbo-ing . If You go to the top of the home page on ls1-tech , there is a button to view all the members , I would go there and pm some of the guys running turbos. Good luck

boosteds10

Do you or anybody else they may glance at this know what the stock compression ratio is for the lm7? And what it would be with the 317 heads?

WS6tx

iTrader: (25)

1999+ LR4 4.8
1999+ LM4/LM7 5.3 Liter Truck
Combustion
Chamber Volume 61.15cc
Compression Ratio 9.5:1
Intake Port Vol: 200cc
Exhaust Port Vol: 70cc
Intake Valve Dia: 1.89-inches
Exhaust Valve Dia:1.55-inches


2001+ LQ4 6.0 Liter Truck
Casting number 12562317
Chamber Volume 71.06cc
Compression Ratio 9.4:1
Intake Port Vol 210cc
Exhaust Port Vol 75cc
Intake Valve Dia 2.00-inches
Exhaust Valve Dia 1.55-inches

Hope This Helps Ya.

boosteds10

This helps alot! Thank you very much!
Now the questions is, should I Switch to the 317s or just stick with the stock 5.3 heads?