Shop owner here....Trying to help a friend out. I have a 2006 Hummer H3 with a blown 5.3L threw a rod. They bought a donor vehicle before talking with me, its a 2007 H3 with a 5.7L. I am looking at all the basic connections, MAF, TPS, CAM PS, Crank PS, they both run air injection. Ideally it would be nice if i can leave the ECU in the 06 body and drop the 5.7L engine in.

Has anyone pulled this swap off if so, did you have to swap the ECU's? Any help would be greatly appreciated. I am trying to get this swap confirmed before I start tackling this.

 

 

you cant confirm if a 5.7L from an 07 will swap into a 06 that originally had a 5.3l? I must be asking the wrong group sorry.

 

 

I see my brain fart now. The 06 has the 3.5 and the 07 has the 3.7. Part of me wants to me to believe it will work, I know if i at least bring the PCM over it should be viable....hmmmm.

 

Others have done 2007 3.7L into 2006s, and they have put 2006 3.5L into 2007s. At a minimum you will have to bring over the 2007 PCM.

Good luck.

 

I just called pcmofnc.com and they told me the swap is feasible but they told em to stick with the 06 PCM. But he would recommend to send the PCM in to them to get tuned to adjust for the larger displacement. Looks like I am going to move forward with this one....

 

I forgot one important thing to mention too, they also did mention the reluctor rings on each engine is the same as well. If they were different you would be SOL and the only way to confirm those is by tearing the engines down and comparing.

 

i thought there was a difference in cam phaseres

 

2008s+ have the different Reluctor Wheel. Either the 2006 PCM will have to be reprogrammed, or 2007 PCM will have have to update the Vin#. I know that if you keep the same motor's PCM (2007 for 2007) it will run until you update it.