[ILLusion]

compatible parts with other gearboxes:

Bushings: version 6 specific
Gears: version 2/3 compatible
Spring Guide: version 2 compatible only (Guarder v2 will NOT fit without modifications)
Spring: version 2/3/7 compatible
Piston: version 2/3/7 compatible (check tooth alignment between the first 3 teeth with the sector gear's teeth)
Piston Head: version 2/3/7 compatible
Cylinder: version 2/3 compatible
Cylinder Head: version 6 specific
Air Seal Nozzle: P90 specific.

Any other parts you need to know?