Verified answer

The jack is what matters. Sometimes it's nice to have a new one just to be sure you don't have any shorts in the wire, but as long as the jacks match, it doesn't matter. I had one for a while that was not attached very tightly, and it caused a staticy sound when I moved in a certain position... great reason for a new lead.

As long as it has the right jack ends, all is good. But remember the better the lead, the better the tone.