Issues with downgrade from 3.4.20021

Probably trying to install the Sync app, voice, and Gracenotes at the same time. Out of space. Remove Gracenotes, install only the Sync app and voice. Being you have a NON-NAV system, there will not be enough room for Gracenotes, most likely.

Tutorial: Removal of Gracenotes - Ford / Guides & Info - CyanLabs Official Community

Tutorial: Sync 3.4 NON-NAV APIM: Failure to Update to Newer Version Sync 3.4 - Ford / Guides & Info - CyanLabs Official Community