When u get the head off carefully clean the tops off of all the pistons in an area close to the edge and indexed at the same place on each piston.Use a vacuum cleaner to catch the debris. Bring each piston to TDC w/ a dial indicator ( careful of the T-chain during all that turning). Using a depth mic, measure and record all crown protrusions above the block parting surface at the area previously cleaned.If they are all uniform, the rods should be okay.If one measures short, that one is likely bent.