I am not familiar with your engine type but if they have located the heat exchanger under the engine or gear
box it is possible that they are relying on thermo syphoning to circulate the oil
through the exchanger and therefor you would need to be careful of where you moved it to. However if the oil
being cooled is pumped through the heat exchanger you should be able to move it to somewhere more convenient.
There are probably a couple of things you need to be careful of: the pump puts out enough pressure to handle any extra head
generated by raising the exchanger, and if the exchanger can drain into the gear
box is there sufficient ullaged volume to allow this without the gear box overflowing.
Both the anode immersed in cooling
fluid, and the dissimilar metals in the heat exchanger, also immersed in the fluid act like a battery
. It is the current
flow between the dissimilar metals which cause the corrosion
of one of them. When you immerse an anode the current
flows through the anode corroding it rather than the metals in the heat exchanger. Consequently both anode and metals being protected must share the fluid and should be in fairly close proximity to each other.
A possible solution might be to screw an elbow
into the holr where the anode fits and then a tube riser so that you screw the anode into the top of the riser, however you would need to ensure that there is a flow through of some sort so that the anode is always bathed in the coolant
flow and not be in an air trap.
An alternative might be to put a T piece in the coolant
inlet and relocate the anode.
Photos and a bit more detail would help.