Gear oil for df200, conflicting part numbers?

[jserr68594]

I'm getting ready to change the gear oil in my 2006 df200. The old oil part number is 990a0-01e80-01Q. This is an 80w 90 oil.

What was sent to me was Suzuki part number 990a0-01E81-01q. It is a straight 90 SAE oil.

Are the two oils compatible? Can I mix them? Is the new Straight 90 weight oil okay for my outdrive?

Thanks in advance!