NH diffs, interchangeability

[WTF]

heyas guys,

im wanting to drop my drive ratio on my NH SWB with the use of the 5.29 diffs, but ive heard that some diffs are different sizes etc.

so what options do i have in order to drop my final drive ratio, so i have better towing in 2H (the larger 33in tyres made towing heavy loads very difficult, i shudder to think what it would be like with 35s!).

i know there is some data on here relating to diffs and transfer cases etc but i was somewhat confused about the diff's dimensions, and whether i can get a configuration that will give me the lower ratio front and rear - what car in a wrecker would i need to look for in order to make it happen, or does anyone have any other solutions/parts i can use?

also will my rear difflock and arb air locker still fit if i locate the lower ratio diff gears?

thanks,

mark