W124 FSM section 03-7021aw provides a piston protrusion spec for the 601/2/3 series. 0.74-0.96 front and rear for a "new" block, 0.96-1.16 for a machined block. It doesn't provide a fore-aft variance spec which would be nice to confirm bent rods before refitting the head.

If you go deeper into the engine, it's pretty obvious to see from piston skirt wear if any rods are bent -



Note the bright patches on #1 and #6. Main and rod bearings on this block were withing installation spec, not just service spec. I'm tearing into another block with similar bright patches on #1 and #2.

Sixto
87 300D