The TIO-540-AF1B is a unique beast, and quite pricey. Although I am just a little past 1,000 hours since overhaul, I am looking down the road and planning financially. I have found that there is a dramatic difference in the price between having a good shop preform the overhaul versus getting a Lycoming zero-time engine. I did a zero-time Lycoming on my C72R a few years ago and have been nothing but pleased. However, the price difference for the AF1B is exceptionally substantial. Is the zero-time engine really worth the substantial difference? I welcome any insight from others that have been down this road.