can i find it in the data folder? if so how do you activate it or replace the x3 slower one?
Depending a bit on how you installed OOO 1.33 Complete, you should have an Oscuro's Oblivion Overhaul folder in your Data folder. In this you'll find an OOO-ADD-ONS folder, with Level_Rates_Modified and some other stuff. If you still have the 1.33 Complete archive, it's there as well.
Just add Level_Rates_Modified_x2.esp and make sure it loads after OOO and you should be good to go.