Toyota tell me that a 4age one will work fine but the unit they recommend mounts in a thermostat housing. The one i am after mounts in the back of the water pump between the bottom hose outlet of the pump and a metal pipe that runs along the side of the block that flows to the bottom of the radiator.
The one Toyota suggests is way too big for this. Inside diameter is around 38 mm.
There is no thermostat housing for the bottom hose.
hrmm, ok.. all the AW11's i have seen whether it be 4age or 4agze have the thermastat in the housing on top of the gearbox.
never heard of one inbetween the water pump and that metal pipe. it goes to the thermastat housing anyways..
if you must mount it there for what ever reason, why not go to a auto parts shop and ask to look at their Tridon thermastat book, it has many thermastats of different diameter and heat ranges. wouldnt be too hard to find the one you are after.