A wall assembly for use in a combustor of a gas turbine engine includes a support shell with a first inner periphery along an axis and a liner panel with a second inner periphery along the axis. The second inner periphery is smaller than the first inner periphery. Another wall assembly for use in a combustor of a gas turbine engine includes an annular grommet mounted between the support shell and the liner panel. The annular grommet defines a contoured inner wall.