there are companies that make a reverse cut gear.... crisman made one for sure, I know at least one TT had/has this set up.
FYI. Reverse cut gears don't fit in standard cut case.
There's a company that makes a third member that uses 8.8" reverse cut gear. I believe it's high9+, but not sure.
Unless the rest of your drivetrain is mounted backwards, putting the 3rd member upside down will make it drive backwards.