Mopar 318 rockers

What is the difference between a 72LT and 712RT?
The 72LT is for exhaust and 712TR for intake?

So I should, on each side (driver and passenger) have from left to right:

72LT / 712RT | 712RT / 72LT | 72LT / 712RT | 712RT / 72LT
That's it ?