super nova

What is a LQ4 and LQ9, and what are the differences, and how do I tell if I have either of them, because I just bought a 6.0L from a local salvage yard

HMFDZ28

iTrader: (16)

An LQ4 has a cable throttle body, an LQ9 has an Electronic throttle body. The Silverado SS and Escalades have the LQ9

Gen3Benz

iTrader: (4)

some LQ4's come with electric throttle too, 03 suburban has electronic throttle, probably more.
dont know of the external differences between the two
dont the LQ9's have flat-top pistons to boost compression?

TJ

iTrader: (10)

lq9 has flat top pistons and a beefier rod.
lq4 03+ all have electronic throttle.

i wouldnt care which i had, both are going to make the same amount of power.
same head, same cam.
i doubt the .6 bump in compression is worth what GM "advertises"
good luck.
lq4 will be MUCH cheaper.
most online auctions and junkyards want more for them used than a brand new longblock costs new.
it came from an SS or a caddy... so it cost a fortune, LOL.

diognes56

iTrader: (3)

Doesn't the LQ9 have aluminum heads where the LQ4 has iron heads? I am not for sure, just something that I have heard.

David

'JustDreamin'

The earlier LQ4s (I think '99 model year, not sure about '00) had iron heads. But the later LQ4's ('01 and newer) use the same alum heads as the LQ9 (or maybe that's the other way around). And the LQ4/LQ9 alum head is basically an LS6 head with a bigger chamber (72cc vs 65cc or so) so they flow pretty well.

'Dreamin'

TJ

iTrader: (10)

iron headed 6.0's are based on 98 ls1 castings.... so stay away from them if maximum HP is your goal.
ive heard that 99-02 were mixed iron/aluminum.
all 03+ are aluminum.
check for the "317" casting # on the corner of the head.