No offense intended to anyone, but the assembly shown is the rotating and the reciprocating assembly. It is made up of the crankshaft, along with the pistons and all attaching hardware (con rods, caps, rod bolts, etc...). In performance-engine building, the weights of all components is taken into consideration and balanced to one another using the lightest of each component as the "standard" with each like-component (con rods with con rods, pistons with pistons, etc.) matched to it by grinding away excess material left in the casting process for that purpose. Typically the crank is balanced first to establish a stable baseline to work from and is accomplished by drilling holes in the counterweights as shown in the picture of Vette's 383 crank. Plug-weights are also sometimes used in the drilled-out recesses to achieve a specific weight by increasing it to correspond with the weight of the reciprocating mass. The harmonic balancer is not a weight per-se, but actually a fluid-filled damper intended to cancel out unwanted and sometimes quite destructive vibrations caused by accoustic harmonics (a cumulative effect of all engine vibrations achieving harmony to the point of catastrophic failure). I hope this didn't muddy the waters, just trying to help...