left/right flapper boxes?
 

I just got new flapper boxes from PP. At first I thought that they had messed up the order because both the left and the right flapper box appear to be indenticle. They are, however, clearly mark left and right. Also I pulled out my old ones and they too are identicle. So I'm confused, are they supposed to be different? Why are they sold as left and right? When I mount them does one simply get mounted upside down?

The original boxes have been superceded I think as the pair I bought were the same as yours. Remember, the lever pulls towards the front of the car to open the valve to let hot air through and that the front of the valve will point towards the outside of the car slightly since the front hose connection is further out than the valve. If I remember one side had the lever on the top too. Good luck.