There's nothing in it, the engines are more or less identical, with the exception of a bracket under the cylinder head nuts on the Defender application.
The gearboxes are the same too, but the Defender has a different gear change setup, which you'll want to use.
Use the complete 90 assembly, but only if the engine is as good as the Disco' one..
You will have to re position the engine mounts on your 110's chassis.