Dear prado 93 guy
if u want to install diff lock on ur prado 93 , the you need to replace the axles. Axles with diff lock motor have a slightly different tub which has a rectangular cut in it . It is going to cost u around 30- 50 k (IMHO) if u want both front and rear diff locks . Contact ustad Rasheed as he is the pioneer in this area 03335214839.
Also i would suggest that go for rear diff locks only . It is going to be cheap , practical and less hassles .
( BTW , my jeep has 96 prado axles with both diff locks )