An apparatus includes a ball plunger post and a valve stem post extending upward from a base, the ball plunger post having a size and a shape of a hydraulic lift adjuster (HLA) of a predefined engine, and the valve stem post having a size and a shape of a valve stem of the predefined engine. The apparatus includes a fixture sized and shaped to receive a switching rocker arm assembly, the switching rocker arm assembly having a first end for pivoting and a second end for latching, and a latch with a latch pin fitting into a latch bore and a latch seat. The apparatus includes a latch rod for positioning within the latch bore to rest upon the latch seat, the latch rod having a hardness higher than that of the latch seat and a same diameter as the latch pin, and adapted for coining the latch seat.