I just changed mine over and used a KE71 cable. The only difference is where it plugs into the back of the instruments the KE cable has a metal bit you have to cut off so you can use the white plastic bit from the '86 cable. And the little right-angle bit where it plugs into the gearbox isnt on the KE speedo cable so you have to use the 86 one.
As long as you have a tool to cut the metal bit off (I used a grinder) its no trouble to swap.
