Stroker 340>416 Build Advice

Have the rotating assembly rebalanced at a good reputable machine shop. Found many packaged rotating assemblies way out of balance from scat. Just a heads up precaution you may want to do before its assembled. My son just had a pro balanced FE Ford 28 grams out. That was the worst one so far. Within 3 grams is good . Zero is the ultimate.
28 grams off ?? wow that is bad never had a problem with my molnar cranks they were all dead nuts on . Luck of the draw