These are the last cylinder heads produced by Rover, new but stored since 1999 hence not cosmetically to high standards, but checked and perfectly servicable as used by the production line. They do not have the by-pass hose hole, heater tap hole, or a provision for the temperature sender in the head itself (the work around for the sender is to use the sandwich plate PEG100030). The threaded screw holes are in place for the heater tap but the heater tap hole is blanked out and will require drilling if required,which is what engine tuners modify when needing a new casting. Cosmetically they look different because they have the alternator fitting holes drilled below the thermostat housing at the front.
These heads have revised casting cores to give a more consistent water temperauture across the head making it the best head ever available