So this is a pic from up above with the handle all the way forward. See how the diverter hits the pump? We cant phsyically get it to go up higher. Strange no? Diverter all the way up I would think gives you more than a three foot high rooster.
Adjust the top cable nut so it is flush with the end of the threads and re-torque the bottom nut.
The rod ends don't need to be threaded all the way on. 3/8" thread engagement (not including the jam nut) should be sufficient. You can do this on both ends of the cable.
If you really want to get ambitious, you can relocate the cable clamp in the shifter assembly.
P.S. I think Jim Brock still has some wedges available.