Matt.
Hardly any part numbers visible so I popped the bearings caps off. 1 5/8 bigs and 1 3/4 mains says 1098 to me. Diagonally split rods, 2-ring camshaft with narrow lobes also says 1098. The odd thing then is the flange for the flywheel with 6 bolt holes and 2 dowel holes. There was also a spare cast backplate with lots of extra holes drilled in it that suggests to me (in hindsight) that someone tried to adapt this engine to fit a Minor gearbox. The bearings are all std size and show barely any signs of use. Metro timing cover and damped pulley. The crank part number appears to be 12G2822 or something like that. The design seems to be that of a 1098 but with the flange straight off of a 1275 Marina (thick and with extra holes)
Anyone want to build a 1098 Minor with an overdrive gearbox???