Re: cable/pully steering
how to determine lenght of cable needed
It's far easier to just buy a roll and cut to fit, the length will depend on the style or routing of your system and the size of your boat, as well as pulley positioning.
The cable isn't expensive and every time I've bought it, it's came as a packaged roll of about 50 feet from the hardware store. None of the marine kits I could find locally were anywhere near long enough since they were meant for sailboats.
I would only stay with the cable and pulley system if I was doing a restoration and was really trying to stay time period correct. Using a Teleflex system saves space and simplifies the whole set up.