A light weight Racing piston is used with this set up also reduce weight. The pistons are TRW 7667 and 7661 dome pistons according to which side valve relief is on. The light weight pistons are connected to the light Aluminum Rods with lightweight racing wrist pins. The Pistons were also lightened and matched in weight. The Pistons were then Gas Ported. Gas porting is the small holes drilled in the top of the piston. This hole lets compression go to the back of the top ring which is only .043 thick. When the engine is on the compression stroke, the pressure in the cylinder blows the ring out against the wall of the cylinder. Then the ring loosens back to normal. The Pistons were then fitted with file fit rings. The rings are thin to reduce friction on the cylinder wall. The top ring is only .043 thick the second ring is 1/16 and the oil ring is 1/8.