Spline Keys Spline Keys couple the splined end of the motorshaft to the splined shaft of the pumphead that comes through the block. To make sure you order the correct part, you will need to count the splines on both shafts and order accordingly. PART # PART DESCRIPTION PRICES 810.916 9 to 16 Spline Key $9.95ea. 9 to 16 Spline Key - $9.95ea. ___ Quantity: