4.2L TD Dual Cab

Am looking into the possibility of building a 4.2L TD or thereabouts dual cab. The main reason being the current factory dual cabs are all around the 3L mark and the extra grunt of a larger TD engine better suits my needs. Have looked into the option of having a wagon 'converted' into a dual cab, but, looking at the other side, wondered whether it is possible to fit such an engine into an existing dual cab. Has anyone seen or heard of this being done successfully?

Thanks.

Regards,

Clayton.