The front flange.
Dual bolt circle
32 Spline
4.25" Bolt Circle (12mm threaded)
4.25" Bolt Circle (non-threaded)
2" Pilot Diameter
Seal Surface 1.94"
Flange Diameter 5.5"
The rear is the factory flange/balancer and it has a dual bolt pattern also. I don't have specs on it.