Well whats the point of owning a Land Rover product then
As for tyre pressures on non-standard fitment tyres and rims...you will just have to work that out by trial and error...
Start at the book values (sticker on the inside of the drivers door jamb) and see how it rides...then work from there.
on 22's, the ride will be hard and harsh, lots of steering kick over pot holes etc that will eventually take its toll on the steering rack and ball joints, be prepared for that.
