I am using the Mag-Hytec Diff covers and the Mag-Hytec trans pan. I like the fit, form and function of these pan and covers. The mounting surface was machined and they were flat. I was able to torque the mounting bolts that were supplied and the surface was sealed, no leaks. As you know there is a drain plug to allow the oil to be drained before removing the pan, less mess. The supplied mounting hardware is 3/16 allen head bolts with flat washers.
Since I am towing a 5er, I wanted to added additional cooling to the transmission the Mag-Hytec pan achieved this. My temperature has been no more than 170F this summer, last year my temps when towing did reach 220F. I have my temperature probe in the pan and I am reading the cooled oil that will go into the transmission. I have been extremal pleased with the pan and covers.