The last gearbox cases from Rover Powertrain dept as used on twin point injection cars. They have the latest strengthened areas and 3 bolt fixing around double roller bearing end retainer. Deeper cut idler gear faces to allow more oil for lubrication of idler train components. Casting number on case is DAM5626.
Previous case was DAM2886 had 4 bolt mainshaft retainer and strengthened idler gear housing---previous to that was DAM4818 with same 0.875 inch idler but not strengthened.