Is there a calibration module that will allow me to use the stock e lockers on my rubi in 4 hi.

 

Superchips flashpaq allows you to run lockers in 4 hi. You do have to keep the unit plugged in while you are running a locker in 4hi. I said a locker because I believe it only allows you to run either the rear or front at one time. You cannot run them both on although I haven't tried yet.

 

Does it also allow for diff re gearing, bigger tyres and re mapping for different fuel types?

 

Yes, yes and not sure on remapping for different fuel types. But it does quite a bit.