Gearbox Oil in 365

We build right angle gear drives and have 1000s of hours test time on lubes. Although we have never run Redline we have run the Mobile shc 75-90. The Mobile Gear Synthetic 75-90 is very similar though they change the additives so that they (additives) will not have a negative reaction with the yellow metals that we all know as synchronizers. It sounds like I am promoting Mobile, but we recieve no funding from Mobile, they seem to have the best information and appear to have done the most research. Our testing seems to confirm their claims.You can purchase Mobile Gear Synthetic at most auto part stores. Don't know about the differential with the clutch pack for the limited slip. The closest to the Spirax would be just a Castrol 80/90 gear lube. Once a gain EP additives may attack your synchros so I wouldn't use them in the transmission. If they have EP they will say so on the label "80/90 EP" I will run the Mobile Gear in the box on my 365GT4 when I get it back (resto). I will say there is no comparison between the synthetic and the mineral oil. Different gearboxes same loads tested same time on the same stand mineral oil black and nasty Mobile synthetic clear units running under 200 degrees F so that the mineral oil is not running above recomended temps.
Rick

 

Did some checking mobil gear LS 75-90 is approved for limited slip diffs.

 

When I checked the diff in my recently purchased 400i, the oil was very clean but a very striking blue color. It is kind of an French racing blue color. Anyone know what brand / type oil this might be?
Ken