Gear Oil....again!

[scourge at cogeco.ca (Scourge)]

Ok so I went to get some Redline gear oil the other day only to find out that the only place I knew of to get it, doesn't sell it anymore. They now only sell this stuff called Royal Purple. It's sounds familliar, but I'm not sure. I looked through the archives but only found one vague reference to it. Anybody know of it, recommend it, or otherwise? Any other oils I might actually be able to get that anyone recommends? I am starting to get the second gear crunch, which some people have said can go away with Redline(I know it's not proven, but it's worth a shot, no debates over that now!!   lol)

That said, what's the difference between GL-4 and GL-5?? Everything I read tells me that GL-4 is good for an 020(4k in this case) and that GL-5 oil will trash my syncro's. This Royal Purple stuff says it's GL-4 and GL-5 compatible. Also, what weight should I be running? They have 85-90 and 90-140 I think(or close to that). I'm in southern Ontario and this car is winter driven, so it sees 35*C in the summer and -15*C(or colder a few times a year) in the winter :D.


Thanks for the help
    -George