A little trick I found to help varify the rear main seal leak repair is to install the oil pan but leave the flywheel off. Tilt the engine back as much as possible and overfill the crankcase to submerge the seal area with oil. Use cheap oil as you will just drain it out later. It may take a few gallons. Let the engine sit as long as you are comfortable and if there are no leaks seen, drain out the oil and finish the assembly as normal. If you have a leak you should be able to easily see where it's coming from without the engine running and the flywheel in the way. I hope this will save you some time. Good luck!