I have a 2000 4x4 that has a tired 5.3, (240 thousand miles).. I just found a 6.0 LQ9 motor that I want to punch out .30 to make it a 408.. Don't know how much trouble that will be and was wondering does anyone have any advice?

Thanks
Mark

 

.30 over is a 370. Gonna need a 4.00 crank as well. Same engine. Externally, as the 5.3, so it's easy. But will def need some tuning a fuel pump, injectors, and built trans I'm sure. What are your goals?

 

Budget 370 can be had fairly cheap.
I built a complete 370 for $3000 oil pan to intake.
Mild build daily driven 400hp at wheels.
https://www.performancetrucks.net/forums/showthread.php?t=516631
That 408 is $2500 for crank rods and pistons alone .
Roughly a 408 short block will be 35-4000$

 

370 is best bang for buck...

 

I have build small and big block Chevy's for the last 35 years but never an LS motor with all the computers.... I want the motor to thump and run well. The truck is heavy ( 4x4 ) so I want the HP and Torque to push the truck down the road.... It has 373 gears with the stock Trans. I know I will have to do some work to the trans and add a little bit of stall. I want it as a daily driver.

 

I have a 2000 silverado 4x4 as well and did a LQ9 swap a while back, Been real happy with it. the link to the whole build thread is below. This was the first time I built an LS motor as well and I left alot of good tech info in the build thread. I went from my 5.3 to the 6.0 lq9 with a good cam and it's my daily driver running 35" tires and still gets decent mileage and moves pretty damn good when I hit the skinny pedal!

https://www.performancetrucks.net/fo...0-swap-472673/

 

Any Issues with the re-tune via the computer?

 

Any issues with the re-tune via the computer? Did you go back with headers or stock exhaust? Thanks so much for the reply...

 

A 370 with a blower will make a ton of power and torque and will still be pretty good on fuel. There are a few for sale on here right now. The Magnusens are perfect for a daily driven truck. Nice thing is that they include the required larger injectors and any local tuner can tune one. There have been a few that have run 11's in a full size truck like yours.

 

I had blackbear performance tune the computer via mail order. Turned out good. went stock manifolds/cats for now since i'm in california but working on re-doing the exhaust and doing some full length pacesetter headers.