MP5 gearbox to M4/Masada gearbox

[Kilo]

Alright so its summer project gun time. I'll either be getting a HK416 or a Masada. My plan is to gut the internals and replace them with a spare gearbox that I have, only issue is its set up for a MP5. I know its the same version II shell, but what all needs to be changed for me to put this gearbox into a HK416(internally an M4) or Masada?

[lt_claws]

trigger, selector plate. Those are 2 i could think of right off. Defiantly some more though.

[Riptide]

Trigger
Selector Plate
Nozzle
Cylinder (if you're really anal about barrel length and all)
Wiring (Rear/Front depending your setup)