<VV> Where to buy GL4 80w90 gear oil locally?

[Charles Lee]

Is there any place to buy GL4 80w90 gear oil locally?
Hopefully less than $20 per quart?

This request is on Facebook too:
https://www.facebook.com/photo.php?fbid=10208980953493691&set=gm.10155232018
129017&type=3&theater

I bought 4 quarts of GL4~GL5 Valvoline Trans Fluid at WalMart, but it's GL5.
NAPA sells the same stuff under their own "NAPA" brand?

I heard that this stuff will ruin my transaxle? How long would that take?

Now I have 4 qts of this stuff that I can't use.

Maybe I can use it just to flush out the watered down old stuff?

Charles Lee