Looing into getting an LQ9, probly from the junkyard. Is there anyway externally to tell the difference between the LQ4 and LQ9?? I know that you have to pull the plugs on the 4.8/5.3 and look at the pistons. Thanks in advance guys... i know that mistakes happen, but if someone was TRYING to rip me off I'd be pissed.

 

compression was main diff, like 9.41:1 on lq4, and 10:1 on the lq9 according to my service information 2000 (from gm dealership)

my lq4 has dish pistons,

Carcraft December 2004 issure says

both LQ4/LQ9 engines can use 317 casting heads, 210/75cc D shape exhaust ports, 71cc chamber.

i guess thing to look for is the dish pistons that the LQ4 has.
lq6 should be flattops.

good luck.

 

thanks for the info, i kinda figured that since that's how the 4.8/5.3 differe, but i didnt want to assume...you know how that is.

 

I don't know if there are any differences other than peeking in a plug hole...

I can check my motor tonight and read off some casting numbers on the block - if there are any? Maybe a few owners of both motors could compare?

 

I dont know of any external differences. Only thing I see on mie is the little 6.0 stamp at the front of the block. Hell maybe it has different block numbers on it, Im not sure. I dont have another motor to compare with. All I knew of was the pistons and rods. Dished on the LQ4 and flat tops in the LQ9. LQ9 has beefier rods too.