Little Joe, I don´t know how much help I can be for you, but, I am currently rebuilding a 74 sportster. I am not an expert mechanic, but I am definitly learning alot as I go. I noticed that you didn´t specify if the leak was top engine or bottom. There are a TON of gaskets and seals on this bike, not just between the crank and the heads.I currently have my entire casing in half and I am going through every inch of this motor. You could have a leak between gearcase and its housing, or it could be a bad checkvalve in the oil pump. I have been told that this is a commom problem with these old bikes. There is a oil pressure switch on the right side of the oil pump,beyond that is a oil pump nipple, then there is a check valve spring with a valve ball. If this spring is weak or ball worn, it will allow oil to seep past and make a big mess. I hope some of this info can be helpful to you because something like this can drive you nuts! Good luck.