The correct engine number prefix for a Leyland Mini 1275LS include:
12H902UH (followed by a series of six numbers). This prefix accounts for the majority of 1275 LS cars.
12H897UH (followed by a series of six numbers). Note, this prefix is less common - 1 example seen.
Like most mini engines, the engine number for a Leyland Mini 1275 LS can be viewed at the front passenger side of the engine. It is at the top of the engine block, just above number 1 spark plug, behind the alternator. You may need to take some degreaser and a light brush to view the number clearly. See the attached images for a better understanding of the location.
Note, an engine number may not be present if the block has been shaved, or the area is otherwise damaged. In such instances, you will need to confirm the engine is a 1275 through other means, but this may not confirm the engine is an original 1275 LS engine. One unique feature of the 1275 LS engine (and all late european 1275 engines), is the presence of timing teeth in front of the crank wheel. These timing teeth were present on late model 1275 engines, and not on earlier Australian engines used in earlier Minis and other BMC models, which relied on the flywheel mark to adjust timing. An image of the timing teeth is shown.
