Look at the side of a piston, where the wrist pin goes through. If the pin hole is offset from center, install the pistons on the rods so the top of the rod will be closest to the camshaft at the top of the stroke. The offset is usually quite small- - - -about 1/16", so you might need to do some measuring to be sure. The pin offset is there to prevent piston slap at low speeds such as idle and part throttle. The oil spit hole in the upper half of the connecting rod big end also points toward the camshaft. Sometimes a piston will have the letter "F" cast into the wrist pin boss, indicating "front".
Jerry
