Thanks C150L. I know there have been some cranks that have broken. Then again, cranks have broken on Lycomings and Continentals also. From what I've gathered, the billet crankshaft available from Dan Wesseman looks to be the way to for anyone concerned about flying a stock crank. I recently met a guy who has several hundred hours on his Corvair (done according to William Wynne's instructions) powered 601. He just did a curiosity tear down and added a couple of upgrades and noted no problems inside. He said it's a great engine. Thanks again.