[James Rogers]

First, you can remove the cap without any problems. The best way to check the clearance is with aluminum foil when the engine is in the car. The rear cap is a forged cap which has to be tinned before pouring and with the inability of many modern builders to properly tin the cap, that could be the problem. First thing I would do is to use a screwdriver to pry the crank forward and measure the clearance between the thrust surface on the crank and the thrust of the bearing. The clearance should be between .004 and .012. Any more than that and you will have the beginnings of a leak to a massive leak when running. I check the bearing clearance by removing the cap and cutting a piece of heavy duty aluminum foil to a size of 2" X 1". Fold the foil in half to make a 1"X1" piece.Insert the starter crank in the front of the engine. Lay the foil in the bottom of the cap on the bearing surface and replace the cap. Torque to 60-80# and try to turn the crank. If you can turn the crank you need to remove the cap and peel one shim off one of the shim packs. This is done with a very sharp knife by picking at one corner and peeling one off when it is lifted on the corner. Replace the cap with the foil still in place and try to turn the crank. If you can still turn it go through the process again removing a shim from the other pack. This is done till the crank gets very hard to turn or won't turn at all with moderately heavy pull on the hand crank. Once you get it to lock up or very hard to turn, remove the cap and take the foil out of the cap and replace it, torque it and, replace the cotters. Reinstall the pan and this should take care of the oil problem. I do know of more than one builder that does not check the clearance of the bearings when fresh. No machinist is so good that he does not ever need to check his work. If you have any questions about this procedure, please ask. Either I or someone here will be sure to help you.

BTW, I don't use or suggest any sealer of any kind on the mating surfaces. When the cap is tightened down, that stuff will squeeze into places that should never have sealer and can stop up channels that can damage the engine.