Carrillo Gen 1 H-beam rods. They were off by about .8 gram from heaviest to lightest... big ends required some adjustment to match tall them all. did final balance taking from the top of the small end. Have all four matched perfectly to hundredths of a gram total weight. Built the jig myself for less than $75. make sure to pull the bearings open and hose them out with brakleen ensuring zero friction and weigh the rods at least 300 times each to eliminate scale hysteresis Lol. Spent $130 on the scale and noticed it crept about .04 gram over 1 hour of activity. weight of clinging oil on these parts in service is substantially more than .01 gram but if you set perfection on the dry weights.... the engine can only be better for it... this is a poop ton of work to build a bomb proof super smooth and powerful engine. Leave no detail for chance.