Clean used as sacrifice Genesis 8:20
Technically this is after the flood but it is before the Covenant so the same rules that were before the flood are still in place.
Seven pairs of clean animals taken on the ark. Genesis 7: 2
However as to what I am sure is your main question as to that predator and omnivores were unclean and herbivores clean before the flood that is something I learned from a Rabbi. Sorry, but I do not have the Talmudic reference at hand and I am fairly sure it is not in the Tanach. I will look it up and Freepmail it to you.
A. Cricket