Just swapped in the aluminum driveshaft from Drive Shaft Shop following this DIY.
Clearance is tight. Get the car as high as possible to make this easier. Put some 2x4s or 4x4s under your jackstands if you can. keep the car as level as possible.
Breaking loose the diff bolts with the car on jackstands was the hardest part---Not much leverage. I did it using a 14mm socket and a breaker bar on the bolt side, 14mm wrench on the nut side. Get all the leverage you can ( use the longest tools you can fit). For me the best working position was laying parallel to the driveshaft.
I was able to re-install and torque the bolts with a torque wrench using a 3/8 wobble extension on a short 14mm socket.
The OEM 10mmX1.0 nuts at the Diff are collared for strength, but they are apparently NOT grade 11 like the bolts... the corners were starting to round off during removal with a standard 14mm box wrench. I sourced some grade10 non-collared replacements just because I wanted fresh hardware.
I went with Pentosin MTF2 for the tranny and Royal Purple Max Gear 75W90 for the diff. New crush washers were sourced from Bell Metrics using info elsewhere on this board.
Went together perfectly and runs fine. Tiny bit more noise at 5-10mph, gone by 30mph. No change in vibration or harshness.
Acceleration is noticeably better, not huge but noticeable. RPMs climb quicker, maybe 10% - 15% quicker by seat of pants dyno.
Useful when your driving includes lots of rapid cycles of acceleration & braking ( such as twisty canyon roads, autocross).
Looking forward to swapping in a lightened flywheel some time down the road when I do a clutch.
Edit: if you want to toss the factory spacer washers,
these grade 12.9 Allen bolts from BelMetric fit fine with some
class 10 nyloc nuts, no spacers required.