Re Oils, i'm about to do mine, and here's what i've decided on (and how much you need according to the R32 shop manual);
Gearbox and front diff - Redline lightweight shockproof (4.1 and 1 litre)
Rear Diff - Redline 75W-90 (1.5 liters)
Engine - Mobil Delvac 1 5W-40 (4.5 litres, or 4.9 with new filter) - because i have some. Next time i'll use a 0W-40 or 5W-40 fully synthetic, maybe even the Delvac again - it will certainly keep the engine clean. I'm also going to add a remote filter mount, oil cooler, and oil temperature gauge. That "report your engine failure" thread is making me paranoid.....and i want to do some track work.
Notes;
- The redline stuff is expensive, but in theory will be good for 300,000 kms so i wont be changing it again. At a minimum go for a fully synthetic 75W-90 for the gearbox.
- Make sure you use an LSD compatible oil in the rear diff
- You can use lightweight shockproof in the rear diff, but apparently the LSD will lock a bit so you'd notice some chatter when turning tightly. I wanted to avoid that, hence the use of the 75W-90.
- Gearbox requires GL-4 spec, diffs require GL-5 spec. FWIW I doubt any fully synths would be lower than GL-5.
HTH,
Kot