Hi there! I have a 2006 GMC Sierra 1500 SLT pickup.. I am wondering how hard it would be to swap in an LQ9. currently it has a LM7.. is it as simple as getting a complete LQ9 engine from a cadillac escalade or equivalent of the same year with its computer and swapping it in? my truck has the 4l60E tranny in it.. or is there wiring issues or other problems? thnx for replying..

 

Plunk in the LQ9 from whatever year you get (03-07 classic is simplest). The truck will start up and actually run not too bad with the stock LM7 tune. You may need to swap your throttle body depending on the year of the engine ( if you get one even).... I think 06 and 07 get all stupid with 03-05 throttle body. None the less your 5.3 has any and all parts you need...... to the point you could just get an LQ9 long block and dress it with all your 5.3's stuff as it's all the same parts anyway. Have the PCM reflashed for the LQ9 and you are done. I would suggest just getting a custom tune from someone and not just getting the stock LQ9 tune.

 

ok thnx!! one more thing what exactly did u mean when u said they get stupid with those years of throttle bodies?? u mean they run like crap?

 

No. Just what is interchangeable.

 

ok so will i actually feel the extra 45 horses and more torque??

 

or how much will i gain???

 

It's worth doing, I'm in the middle of an LQ4/80E swap now. If you can swing it, put a cam in it before you can install it.

 

The cam is weak in the LQ4 and LQ9 but even stock for stock it's no comparison between the LM7 5.3 and a LQ9.