Depends on what model of King. I am putting the 12.5" Wild 1's apes on my Custom. Wild 1's say I need to put 4" over clutch, and 3" over throttle, idle, and brake. I'll let you know how it turns out.
Wild 1 will set you up for failure. I have Wild 1 502s and they told me +6 clutch and +4 Throttle/Idle. Luckily someone posted they had the same bike as me and went +6 on the clutch and it broke after about a year. I decided to order the bars and measure. I came up with a +8 clutch and +6 throttle/idle and added 12" for the wiring harness. Everything turned out perfect. I would highly recommend you mount the bars and measure. If not order them a little longer than shorter.