GL4 gear oil- where to get?

I've searched all the local parts stores and I can not find GL4 gear oil for my 4 speed. What I've found says it replaces GL4 and GL5. What are my options?

Amsoil is what I am using for the NV4500 that is GL4 rated.

I also found some dexron gear oil that is GL4 rated for the NV4500

I looked at a pensoil full syn gear oil for the sycromesh that was GL4 rated

IIRC royal purple has a GL4 gear oil as well as lucus oil in full syn GL4

I have the amsoil on the shelf and the trans is full of the dexron NV4500 oil now.

A good alternative would be Redline MT90 manual transmission fluid. Available from Summit and others.

I agree. for got that one.

I ordered some from Amazon.

I use valvoline synchromesh it's GL4.
I called Valvoline and they say do not use GL5 in A833 transmissions. GL5 will eat Yellow metal they said.

correct yellow metal AND carbon fiber syncos in the NV4500

Got mine from Summit, Brad Penn classic GL-4. Works great!

Napa has Sta-Lube 85w-90 GL4 on the shelf typically. Can get gallons or quarts.