What Oil to use with a KAAZ diff

What oil are those of you with a Kaaz diff using.

KAAZ says
"It is important to use 80W/90 GL-5 specification gear oil on Kaaz LSD. We highly recommend using our own Kaaz LSD fluid. DO NOT USE SYNTHETIC BASE OIL ON KAAZ LSD. Kaaz LSD may not function smoothly."

Was going to use somehting such as Redline MTL or MT90 but they are synthetic, same as the Silkolene 75W/90

Basically leaves me using an off the shelf type oil at the local auto parts store which I don't really feel comportable with, or the Kaaz Oil.

I would only use the KAAZ fluid. Syn gear oil is not good for a clutch type LSD.

Blake

I use only the KAAZ.