RKT says you can "jet down" 2 sizes with his heads. SLP says to "jet up" 2 sizes with their pipe, so one off-sets the other. I run this setup on my carbed KK and still run a little rich using cats jetting chart.
A fuel controller on a stock KK with efi will help lean out the fat midrange and allow finite adjustments throughout the fuel curve that give it a more solid torque curve. Any mods and I would personally suggest you have a BD box.
BB
I ran a speedwerx single with a rkt head no control box 6 to 9000 feet. I ended up with a controler to lean out the fat midrange. It worked great for me! Now its a 975 and I added very little fuel over my 900 settings. Stock tune is very rich! On mine anyways!