heater box adjustment 356sc

[Peter Roberts]

Going for a long run on sunday and forecast is " very cold" so want to make sure my heater box works efficiently.
There must have been lots of posts on this and it gets complicated but i have some simple questions.
1) The control lever in front of the gearstick. Is down for no heat into the cat and up for heat in the car.
1) The forward round control boxes. Which position of the arm is this open to heat the car. I believe it is spring loaded. Is the spring return the open position to heat the car or is it the closed position. they are installed there is no way to visually check.
As long as my forward round control boxes are open i am not worried about the back flaps as i can adjust these or just jam them closed with a half inch gap.