I finally recieved the last part (switch) to do the swap. Has anyone had any success at getting the parking assist to work also? If so what did they (dealer) have to do to get it to work?

 

If you have a the sensor in the rear bumper then the parking assist should work. If it does not you can always to it to the dealer to haveparking assistreprogrammed.

 

By virtue of the fact that you are adding DL3 mirrors that tells me you have a DL8 mirror equipped non-LTZ or Z71 Tahoe. This means that you don't have memory seats. I understand that the mirror position info is stored in the samememory module that supports the seats. Therefore, park assist (aka "curb tilt") can not be made towork with your vehicle. Every other DL3 function will work after programming the DDS & PDS modules.
Review the following post:
https://chevroletforum.com/m_11921/tm.htm

 

I have the LT1 and I do have the sensors in the bumper. I think others have got it to work on a LT1 just don't what the dealers had to do. I'll be installing everything tomorrow so I'll let you guys know how it turn out.