how can you tell if your looking at an lq9 what marking are you looking for

 

Look at the pistons, if they are dished then its a LQ4 if it has flat pistons then its a LQ9.

 

Vin number or knowing what it came out of. Other than that you'd have to look at the piston tops.

 

ya and block should be iron and will have 6.0l stamped on it

 

Hey guys, I just want to make sure but I think I bought an LQ9 what was supposed to be an LQ4. I took the heads off and checked everything out and the motor supposedly came out of a 2006 and it's supposed to be an LQ4, the wreckers never told me the model though. I just assumed it was a regualr sierra, the weird thing is the pistons are not dished. Did they change the LQ4 piston in 06 or do I have an LQ9. Either way I'm happy. Any advice would be great thanks.

 

AFAIK, all LQ4s have dished pistons, and all LQ9s have flat topped pistons. Does it have 6.0 cast into the back of the block?

 

Hey guys, I just want to make sure but I think I bought an LQ9 what was supposed to be an LQ4. I took the heads off and checked everything out and the motor supposedly came out of a 2006 and it's supposed to be an LQ4, the wreckers never told me the model though. I just assumed it was a regualr sierra, the weird thing is the pistons are not dished. Did they change the LQ4 piston in 06 or do I have an LQ9. Either way I'm happy. Any advice would be great thanks.

 

sorry my computer screwed up and replyed the same thing again,

It's definitley a 6.0 just wasn't sure about the piston situation

 

Now the other question is will it screw up my stock computer or will it run ok until I get a tune done in a couple months when I get some money

 

The timing tables are certainly going to be different for the two, since the LQ9 has considerably higher compression.