You need to make sure all gears are in neutral..
When they are the Hurst shifter lever will move smoothly left to right..
When the gears are all in neutral the shift arms should line up, some Hurst shifters have a hole that you can put a drill bit through. Next adjust the shift arms if needed when in neutral, if all is well then putting into reverse is EZ move the lever to the left and up..

Just my $0.02..