Abstract: A horizontal arm is cantilevered from a lock position location so that a ball is suspended by a line from the free end of the arm. The line extends through the arm and exits at the lock position location so that the height of the ball can be adjusted by controlling an appropriate length of line. The arm is designed to allow the ball to drop free when its momentum is spent without the line becoming wrapped around the arm. The lock position location includes a position locator that extends from the arm and has a polygonal cross-section. The position locator is received by a complementary lock position receptor in the form of a recess with a polygonal cross-section that complements the cross-section of the lock projection. The attachment permits the ready dismantlement of the arm for storage or transport to another location, while simultaneously providing against inadvertent rotation of the arm during ball handling or ball hitting practice. It also permits easy adaptation to different sports--e.g.

Abstract: A convertible intake manifold for a V-block engine has a base member and an interchangeable center runner member isolated therefrom. The base member has a coolant crossover section at one end; a distributor boss section at a second end opposite the one end; an engine valley cover section between the coolant crossover section and the distributor boss section; and a pair of port sealing sections, one on either side of the engine valley cover section between the coolant crossover section and the distributor boss section. The port sealing sections have a thickness equal to or less than the thickness of the remaining base member sections for allowing maximum flexibility in selecting a runner configuration for the center runner member. The center runner member may have any runner configuration with runner mating faces configured to be interchangeably attached to the V-block engine without removing the base member.