That part number you referenced is for a kit to upgrade to bluetooth iPilot, but not the most recent version with “link.”
If you let me know which version of Powerdrive you have (v1, v2, or the current version) as well as the year it was made, I might be able to point you in the right direction.
I recently upgrade a Powerdrive v2 from approximately 2008 with a new bluetooth iPilot head. Total game-changer on our recent week-long trip. All the time I used to spend on boat control to get my fishing partners in good spots was minimized to pushing a dang button. I spent all that time fishing myself instead of messing with an anchor, drift socks, etc. Autopilot also made my life loads easier.