I just re-read your first post and 8 quarts of fluid is not enough especially with a deep pan. Did you install the extension for the filter and torque the valve body bolts because you could be sucking air. I agree that you should drop the pan and look for debris. If you don’t find anything put it back together and put the correct amount of fluid in it. My guess is that with the deep pan and the 9-1/2” converter it should take about the same amount of fluid as a stock transmission takes.
