stock stroke and rod = 54mm and 110 rods, uses regular pistons
stock stroke and long rod = 54mm and 115 rods, uses 795 series pistons
4mm and short rod = 58mm and 110 rods, i think uses regular pistons
4mm long rod = 58mm and 115 rods(most common), uses 795 pistons, cut domes
longer rod isnt gonna give you anymore power, just reliability. to get more power you need stroke. go with the 4mm long rod crank(4mm and 115 rods)