Sorry but no...you'll need a minimum of a Digiflight IIVSG to hook to a GRT....as it uses ARINC 429 communication for the vertical steering commands (as well as GPSS lateral), and the ADI Pilot uses only serial (which is only good for lateral - non GPSS commands).
If you stick with the Digiflight IIVSG or above, it'll work fine.
Stein.