After reading the STC section of the FSM, I will scope the power steering solenoid valve and document the duty cycle at different vehicle speeds and engine RPM. Ideally I would like the power steering assist to be much less and CONSTANT.
A lower average voltage at the PSSV (~2 volts) = the reduced assist we experience at 60 mph.
Something like this may be the solution:
AutoSpeed - Modifying Speed-Sensitive Power Steering