Synthetic gear oils

[james accordino]

Is anyone running an over-the-counter synthetic gear
oil in their tranny or diff?  I'm talking about Mobil,
Valvoline, etc. that I can buy at any Autozone or
what.  I know about Redline, but nobody here stocks
it, and it is kind of expensive, heck Mobil syn. is
expensive.  I already used their oil and grease, and
like both of them very much.  Please don't tell me
about any other exotic gear oils that I can't just go
and buy.  They all say that they now have formulated
it so it does not damage brass, copper or bronze
parts.

Thanks for your input
Jim Accordino