Has anyone used Redline MT-90 oil in there rear end. I have a '86 base without the limited slip rearend. On the back of the bottle of redline it says that you can use it in rearends, except those that require GL-5 gear lub. The haynes manual says that GL-5 lub should be used in my rearend. Since I don't have the limited slip rearend can I use the MT-90?