Lookig for someone who has installed a B&M cable operated shifter,,

5 foot cable is typical, just insulate and keep it away from heat.

Here's some instructions for the B&M ratchet shifters for reference.

[ame="http://static.summitracing.com/global/images/instructions/bmm-80840%20&%2080842.pdf"]http://static.summitracing.com/global/images/instructions/bmm-80840%20&%2080842.pdf[/ame]