EGR's job is not to "reburn" unburned stuff, but to cool the combustion chamber by running unburnable air through, thereby reducing NOx (which is caused solely by high temps and pressure, it has nothing to do with combustion itself). EGR has the added benefit of reducing knocking (pinging).

In the 70's, EGR was a performance killer, but now, engines are designed with it, in fact, typically need EGR to function properly.

I'm not sure what the effects will be on the 3.5L, but it might be worth not taking the chance if there is any other way around this...

Nate