Changing Pin Output

Hi

I am making an autonomous boat with two motors. In the rover mode pixhawk has Pin 1 for steering and Pin 3 for throttle. Is it possible to map other pins so that they also output throttle and steering.
I have been looking at the RC# Function but they dont have the throttle or steering commands as options in mission planner.

This way I can have two servos for steering and two motors receiving the same throttle command. Or am i going around this the wrong way and should just parallel (splice) the signal cables to the each motor ESC from Pin 3 and the same for steering?

Thank you,

@morganwatts,
Why did you post in the ArduRover Forum and not the ArduBoat Forum?
Since you are using two motors, you might want to consider using skid steering instead of rudder steering.
Try here
Regards,
TCIII AVD

Sorry was not aware of the ArduBoat Forum. Will post there instead.
I have my heart set on using a rudder system as it has better control with my boat design. If I use the skid steer is there a way to set it so that both motors receive the same input from one channel on the transmitter (in manual mode)?

@morganwatts,
In the skid steering mode, just like the servo steering mode, the roll joystick controls right/left turns while the pitch joystick controls the speed backwards and forwards. As long as the roll joystick is centered the boat will move in a straight line forward at a speed determined by the pitch joystick position.
Skid steering requires that each motor have its own channel.
Regards,
TCIII AVD