There are several different versions of the Redline Fluid and they cover a wide range of uses and abuses.
The Redline 75W90 NS actually lacks some of the friction modifiers found in the regular 75W90 which makes it less slippery and ok to use in a transmission and more aggressive in a differential. That does not mean use it! Please keep reading.......
We have been using Redline for some time at the shop and the fluids we use for the following applications are....
We use the normal 75W90 as Spearfish and several others have already stated for the differential. You can find it on our site
HERE.
We have recently begun using Redline's MT-85 for transmission fluid. We have been using the MT-90 in 300ZX's for some time but this fluid did not work well in 350Z and 370Z's. Redline specifically lists this fluid for use in the 370Z. You can see it on their site
HERE. I really appreciate a customer and forum member for pointing this fluid out to us. The MT-85 fluid can be found on our site
HERE.
Finally you can find the metal washers for the drain plugs on our site
HERE.
This is what we have found works well in the majority of 370Z applications. If you are using your car for some extreme application you may want to look into another Redline fluid for your car but so far these fluids have worked well.