The manual describes a proprietary form factor. If you are hoping to swap this board into a standard ATX case, you will likely run into issues with the I/O shield and stand-off alignment.
The Maintenance and Service Guide provides a complete illustrated parts catalog and removal/replacement procedures for the motherboard. Hp Z2 G4 Motherboard Manual
However, finding the specific documentation for this chassis—distinguishing between the Tower, Small Form Factor (SFF), and G4 Workstation editions—can be surprisingly difficult. Official support pages often bury technical white papers under driver downloads, leaving users scrambling for pinout diagrams and jumper configurations. The manual describes a proprietary form factor