Is the transmission in my 2007 Lt 3.5l transmission went out and I was wondering if that transmission is interchangeable with any other motors.because I have a friend with a savage yard. Any help would be appreciated

 

I believe with grand prix's they are. I know that the 06-07 ss uses the same as the GXP. from 04+

 

Yes, just ensure you get something with a 2.86 differential or I can program the TCM if you get something with a 3.05 or 3.29. Buick Lucerne with the 3800 or 09+ with the 3.9 for example had the 2.86 diff and almost guaranteed to have been driven gentley, worth looking for.