I know the 6.0L was put in the trucks from 99+ and in 01 they got aluminum heads. Disregarding the top end are there any differences in the shortblock from year to year? Is one year better than another? Thanks!

-Sly

 

Not sure of the complete answer, but I've got part of it.

LQ4 (6.0) and LQ9 (6.0) are different short blocks. Specifically the pistons change. Flattops (LQ9) vs Dished (LQ4). Also, I understand rods are beefier on the LQ9.

But since the LQ9 didn't come out until '02, I'm not sure that you were considering those years.


I don't know much about the early LQ4's besides they have less desirable heads. That's all I needed to find out to rule them out (I'll be looking for a complete running motor to drop in 1st, then worry about a rebuild once everything runs).

'Dreamin'

 

I am curious on this also. The guys who did my cam swap suggested acquiring a set of 6 liter heads, I am assuming that the LQ9's would be the most desirable.

 

Yes the LQ4 heads are cast iron if I remember correctly. The LQ9 heads are the same head as the LS6 except for the combustion chamber size being larger. The ports are the same.

-Sly

 

You want an 02+ LQ4. Just keep in mind when you look at some 6.0's they need to have 317 aluminum heads on them. 317 being the cast number. LQ9 uses the same ones. You do NOT want the iron heads. The 317's are bigger chambered ZO6 heads. Do not put a set of 6.0 heads on your truck, its pointless unless you are running F/I. The larger comb. chamber will only lower your compression on a 5.3. Not a good idea.

 

Cool, my main concern is the shortblock. I already have heads and everything else needed. Thanks

-Sly

 

Block is the same.

 

Thanks for the info on the heads. I did a little further info on them and read about only using them for F/I. But thanks anyways.

 

The shortblock is NOT the same. The block is the same, but the crank is longer in the 99-01 (iron head) 6.0's and will only work with a 4L80E. Unless you are going to be putting a 4L80E behind it, or switching out the crank then find an 01-up (aluminum head) engine. Also the LQ9's(SS trucks Denalis, and escalades) do have quite a bit beefier rods than the LQ4. I was really suprised when I saw the difference. The LQ4 rods can still take lots of abuse as parish showed though.

Aaron

 

all alum cylinder heads on 6.0 engines are the same.. the different HP ratings are from the use of slightly higher compression pistons in the LQ9 and the corresponding higher octane gas/tuning that goes with it... READ THE OWNERS MANUAL PEOPLE!!!