Has anyone used Amsoil synthetic Transmission lube 75W-90 GL-4 in their 1969 4 speed?

We can agree on that. And unlike Amsoil, which has great products, M$'s products are for the most part, inferior to other similar offerings from other sources (open!).

So you see, I'm not really an incorrigible zealot. Just very opinionated. And I don't usually push my opinions online anywhere if they are not backed up with personal experience.
Opinionated? Something else we share. Check out my "Windows error messages" thread. When you posted the above it reminded me of those.