Rear main vs tranny input seal leak

[Jac Mac]

Two things, you mentioned the dip stick had popped out... while this could indicate excess blow by, it sometimes occurs when the dip stick hits a pan baffle plate, in turn if you read the oil level from a dip stick that is being deflected internally by a baffle it can give a crook over full oil level and result in you filling the pan above the optimum level, if your stroker crank is dipping into the oil creating excessive windage you will experience more oil leaks and pressurisation.
Other thing I would try is a vented coke bottle & larger plastic tube to the PCV grommet on the rocker cover ( NO PCV ) and a short drive to see how much oil gets pushed into the bottle