If your machine shop doesn't ask for ALL rotating parts, then find a new shop fast!!!

They should want crankshaft, rods, pistons, pins, balancer, flywheel (or flexplate), pressure plate, and rod bolts.

If they ASSUME that all rods and all pistons weigh equally without actually checking them, you need to shop for a new machinist.

Even the rods themselves should be beam balanced for big-end and small-end weights.