The pump and case half will go in place together. Keep the pump in position to ensure the oil tube is engaged properly. Center the case to prevent smearing sealant as you bring the case halves into alignment and engage them. Use the dowels as guides, and keep the faces parallel. The mode fork rail must fit properly through the rear case bore. All the parts should align as you bring the halves together evenly and snugly. I use Loctite 242 on bolt threads and finger-tighten the two dowel bolts to keep the case halves aligned.