Subaru STi R-180 differential cover vs Perrin R-180 finned cover

Note side placement of drain & fill plugs on Perrin cover. I tapped breather hole for a 1/4 NPT barb fitting to run a catch can. This cover gives 1/3 L more fluid capacity than stock. Perrin part # is PSP-SUS-510. Did they have the 510 in mind? Hmmm. Torque to 22 or 32 ft-lbs, depending on which spec you follow. Drain plugs are 36 ft-lbs.