Cant do it without splitting the cases. If you mount it in an engine stand you can do it without having to remove the top end. PERSONALLY, If you're going to split the cases, DO the Top End too. Spend the money to get some quality internal parts (Main Studs, Cylinder Studs, Solid Shift Shafts, etc.) So hopefully you wont have to split it open again for a long time (or ever).