With the valvolene 80w90, I bought a quart and noticed it didn’t say it was for manual transmissions. I had an older bottle of it and looked at the label and it did list manual transmissions. All the text was the same except for that. I poked around on the internet and found discussions on valvolene putting in limited slip additives and that it eats the brass synchros in transmissions. The new bottles don’t warn you not to use it in transmissions. Just doesn’t list transmissions as the recommended use
