That is the Austin Princess 3 litre motor from '68-on.
Like the MGC motor, but the oil sump is at the front. Block is a different casting, but rotating parts are the same.
That is a power steering pump on the left side of the motor. The pump reservoir is what looks like an oil filter. On the right side was a hydraulic pump for the autoleveling suspension system. Mechanical fuel pump as well.
Gearbox looks like the MGC overdrive box, but with a longer shifter linkage for the saloon car instead of the shorter linkage for the MG sports car.
C Ya,
Mark Miller
AMGCR Tech Editor