I installed v2.6 and cannot use it because there is no phone.app, and installing a 3rd party phone.app still doesnt apply you receive calls or hang up a call afterwards.
Flash v2.2 rom first
Then reboot to twrp
Dont wipe anything and dirty flash v2.6
You will get stock phone dialer+contact app on v2.6
Infamous rom v2.2 kitkat
Infamous rom 2.6 kitkat