I recently went through this same problem. I first noticed my fresh engine oil would look cooked after a short drive then I noticed my crank floating with .080 end play with less than 100 miles on a fresh build. I pulled the oil pan and checked the mains and they looked like 250,000 miles were ran on it and the thrust bearing was totally washed. Bill (Wild Child) Doucet found that the wrong bearings were used on the build. The mains that were used did not have the proper chamfer for my crank to flow the oil, they were more for the stock crank. He fixed my problem on the bottom end, now I'm busting transmissions. Good luck.