There are 2 troops of gorillas at the Pangani trail. The first group you see is the family group which recently had two babies. But once you get to the rope bridge, the bachelor group is to your left.
This 2nd group can be very impressive to see when they are all riled up. Here's a hint, they usually are right before they go in for the night, Try to be there around 4:45.
By Safari Mike