We were out of them for about 3 years because we sent Bob at Modern Cylinder head a pallet of 50 heads to CNC port for us. The 3 years passed as we kept waiting, thinking and "hoping" we would get them back, and then customers started telling us they were buying our heads directly from him, so he was selling the heads and pocketing 100% of the money for himself. We even offered a reward if anyone could get the heads back, and we had a couple people go to his shop and demand to see and/or collect the heads, and they were just given some kind of excuse and sent away. Likely all the heads are long gone now. So once we gave up hope on that, we had to find a new 5 axis CNC shop, which we did. In a few more months we should have them back in stock, and from that point there should be regular enough production runs that we won't normally be out of stock again.