I have 38x15 on the back and im putting 18.4x38 tyres on them, i want to keep it relatively level so my problem is front wheels.
i have worked out i think

rear
68.9" overall height new tyre 18.4 38
57.7" overall height original tyre 12.4 36
11.2" difference in height on new tyres
front
32" overall height original tyre
35.5" overall height new tyre 12.00-18
38.2" overall height new tyre 11.00-16 also 36.6
35.4" overall height new tyre 10.00-16
so am i correct in saying that i need a tyre for the front to be a overall height of 43" to keep it level? if so what the hell do i put on the front?