Just bought a second hand HT18 (4.2td factory turbo) unit off ebay, all genuine.

Wanting to replace the aftermarket turbo on my Patrol which is water & oil cooled.

The HT18 turbo I just bought is only oil cooled it seems. Can I just plug the water cooling system up and just use the oil feed & drain? Or do I actually need a turbo that has water cooling? I could plug the water feed and drain up easily enough but would that cause problems?

Also, why did they release 2 different types of turbos? One being water & oil cooled, the other being just oil cooled. Is one better than the other?

Cheers!