From what I can see in your image that it is possibly a S3 as the bellhousing doesn't have the clutch cross shaft hole, it would have a casting down under on the lhs for the clutch slave cylinder, the G/box number on the Left side nr the selectors would give some clues also S3 G/box cases have the Leyland "L" cast on it and some ? ribs cast into it, cheers
Bookmarks