I will check that when it is installed,, you can change the rpm with tire size,, I am running 275-35-19 they are 26.6 tall and 285-35-19 are 26.9 tall and both fit on our car. My Dr's are 26.0 so i can test both sizes I am having some snap rings cut down to get the backlash so next week i will build and install into my car and test for a few weeks. jim