Are they the same or is wiring harness for one different than for the other?

 

I can't say for sure, but the wiring "should" be the same. What is definitely different is the operating system. There are multiple threads on the HPT forums about problems with the gmpp version.

 

So swapping the GMPP E67 for a production car E67 shoulnt have any issues.

 

The ECM hardware is the same & pinouts the same last time I checked but GMPP version is "stripped down" calibration wise to just do N/A GMPP crate conversions with the GMPP harness. Production E67's take some setting up to quieten down the DTC's etc.