el block with au head i think

'Hybrid' Six Cylinder:

Introduced in January 1998, the 'hybrid' six (as it was known internal to Fords - far different to the now usual connotation associated with the word 'hybrid' referring to a combined electro/internal combustion engine) was introduced to allow the early conversion of many of the Geelong machine lines to AU specifications. Externally the engines were identical to the earlier EL Falcon engine however featured full AU specification blocks as well as the AU's low inertia valve train. Unfortunately this did not extend to the AU's head, head studs or head gasket so these engines are still subject to head gasket failure as a routine part of ownership. This change did however involve changing the normally parallel valve springs to the newer conical AU items requiring new tools when servicing.

The valve stem seal was also redesigned in these engines to accommodate the thinner stem of the inlet and exhaust valves. Included in the redesign was a new installation specification for the valve stem seal (depth) so check your work shop manual for the appropriate specs if you come across one of these. The block change necessitated a special 'hybrid' crankshaft to be made, with large main bearings to suite the AU block and EL size big ends to allow the EL spec conrods still to be used. The hybrid crankshaft can be identified by the letters 'VR' cast into it verses 'WR' which signifies a full AU spec crankshaft. There was little doubt that this was the best six cylinder to date - only eclipsed by the AU engine itself.

Actually,

AU Block, Custom Crank, EL Pistons/rods, not sure about the head, but has AU rocker gear and cam is different too.