I had a similar problem with my Cleveland. You may have already don this, but here goes. Put allen setscrews in the 3 center main bearing feeds. They need to have a .065" hole drilled in the center. Tap the block so they will screw in, use thread sealant. Also, install the front cam bearing with the
oil feed hole offset so that the feed hole in the block is half covered with the bearing. The bearing and block have 2 feed holes, so they won't starve for
oil. I have about 7k miles since this oiling modification, and it is fine. Be sure to use a good high volume
oil pump. Any other questions, email me. good luck. Chris