Anybody hear of crankshafts breaking behind the harmonic balancer on these engines. I bought one awhile back and I really liked it( great torque and power) right up until the crank broke about 90 miles from home on a Sunday night(engine has about 12,000 miles on it). Water pump, alternator, and power steering pump is all that was running off the pulleys on the balancer. It looks like a crack started in the keyway and worked it's way around until it snapped, no warning, running fine, and then SNAP!!! I haven't pulled it apart yet or contacted the GM dealer I bought it from, I wanted some input from anyone who might know if this is a problem with this engine, or just bad luck on this particular engine. I don't want to put it back together with another GM crank if this is going to happen every 12,000 miles.