so i had my engine balanced. being that it is externally balanced, they added some weight to my flexplate by adding some "beads of welding" - that's good knowledgeable terminology for some melted metal stuff to add weight in certain places on the flexplate. well, here i am going to swap to the sm465 in about 3 months and i'm curious to know how much this swap might affect the longevity of my engine because i'll be losing the balanced flexplate for an unbalanced flywheel. my machinist said he could attempt to match balance the flywheel to my current flexplate, but that he couldn't guarantee it would be as perfect as when he's got the whole crank/piston/harmonic balancer/flywheel assembly - makes sense. anyway, he says it will probably run about $100 to match balance the flywheel. is this worth it? lets hear some tech discussion/theory behind all these responses please!