LQ9 is the HO version of the GM LQ4 6.0 truck engine. Basically the truck version of the LS2 that was used in the 05/06 GTO. The block has the larger 4" bore vs the smaller bore used in the LS1 engines. The head castings are identical to the Z06 heads except they have a larger combustion chamber. They flow identical numbers. They use the 317 heads (LQ9 heads) when doing a turbo LS1. The only difference between the LQ4 and LQ9 is that the LQ4 has a small dish in the middle of the piston for 9.4:1cr and LQ9 uses flat tops for 10:1cr. Factory ratings are 335hp and 365torq (LQ4) vs 345hp and 380torq (LQ9) respectively. The LQ4 was mainly used inthe 2500 and 3500 trucks and vans. The LQ9 was used in the 02 - 07 Silverado SS, GMC Denali and the Escalades. The one I have came out of a 2004 Escalade.

Dont feel bad,.. I had a learning curve to go through and still trying to cram it all in. I gave up on Chevy engines when the LT1's came out,.. so the LSx motors were completely alien to me. I never saw myself building anything other then a SBC if I ever did another Chevy motor,.. yet here I am. I just couldnt pass up the price of this motor, how easy it is to make 400+ HP out of them and how easy it is to make it work in a fox body. Oh,.. and how easy and affordable the 6.0 blocks are to stroke.

I'm not touching the long block with the exception of swapping the cam. I may get bored and port the heads myself if Bryan isnt done with my car soon. According to the guys on LS1tech I should be at around 400/425hp to the wheels with my intake, cam and carb choice and I dont have to rev it to the moon to make it happen. The cam I chose is only rated 1500 - 6500 RPM with the split plenum intake I chose. I'm not building this motor to be a race motor. My wife will be using the car as a daily driver. Reliability and modest fuel economy were my primary goals. But I fudged a little with fuel economy when choosing the cam I did. But it should still average 20/21 mpg and see up to 25 mpg on the highway. I'm taking out the 4.10 and swapping in either the 3.73 I have now or may see if I can trade for a 3.55 gear.

Performance wise you and I will be on even ground motor to motor,.. and if you decide to put a power adder on I do have plans to add an NOS Cheater kit. My car should weigh in at around 3200 with my fat ass in the seat,.. or right at 3000 with my wife behind the wheel. I'm guessing some mid 11's on motor if I can get it to hook and mid 10's should be a 150 shot away. Thats why I really want us to go have some fun when you get yours on the road. Get some video of our shenanigans and have something to tell our grand kids about. You know,.. the shit we used to do as kids.

Hurst