Steering

[steplift20]

1978 wellcraft steplift
150 mercury outboard
That's what I have, what it need to know is
What steering cable length do I need, I think mine is to long,
What mechanical system should I get, I have a no feedback 4.2
And do I have to take the motor off to get the new cable on
I would like to know what you guys use, and advice on getting it in
Thanks for any info
My steering now is to hard to turn can't seem to loosen it