My 1994 Nc 39 was fitted with a Autohelm 300, Autohelm ST6000, and a type 2 hydraulic pump and ram when she was built. I am not sure what size the ram is.
I upgraded the electronic boxes to the latest Raymarine autopilot this year. ACU 400, EV1, two P70s, rudder reference unit, and SeatalkNG backbone.
As the Type 2 pump and drive were working fine I took the decision not to change these. My hydraulic systems on the boat have always worked fine since buying the boat