Notes:
1. Please don't put the vent directly above the ring gear, unless you want to use your ring for a pump and run that vent line back into the trans as a return line (that is a joke). The rotation of the ring gear will pump oil into that vent and your transmission life will be substantially cut short when the oil runs out. I know of at least one Albins where this mistake was made. Trans only made it 15 mins into its inaugural run off the trailer.
2. The ring gear will always* be located on the drivers/left side of the trans, regardless of mid or rear engine orientation.
(* the only time the ring gear is on the passenger side, would be if you are running a reverse rotation engine (Honda B16, Corvair) that spins the input shaft backwards, or if you literally flipped your transaxle upside down to run it as a mid-engine, instead of swapping the diff/ring gear to the proper side.)
If you are going to drill and tap a hole for a vent line above the diff, please make sure to locate that hole to the passenger/right side of the center rib which will be opposite the ring gear. Run a line straight up a few inches then straight back out the car. Do not put any loops or low spots in the vent line where oil can collect, then act as a syphon that will pull more oil through the vent line as it gets pushed through.