LA with sinle groove bottom pulley

the cast iron water pump uses a 2 11/16 deep pulley. the cast aluminum pump uses a 3" deep pulley when set up with the correct non-air brackets. the belt wraps around the pump, the alt and inside groove of the crank pulley. the optional power steering belt wraps around the outside crank groove and the PS pump pulley. the bottom pic is the shorter WP pulley. you can visually see the difference in style. and just to confuse things more , the BB non air uses the same shorter WP pulley only its a larger diameter