An assembly for a production string with a downhole pump is disclosed which makes use of the polished bore in the top of the liner already installed in the wellbore. Lugs on the assembly align themselves with longitudinal grooves in the top of the liner assembly as an antirotation feature for when the downhole pump is operated. A signaling assembly, involving a collet which can be ultimately released, gives the surface personnel the feedback they need to know that the assembly has been set in the proper place in the top of the liner string, as opposed to another location in the wellbore. Seals, preferably stacks of opposed chevron seals, can be used to bridge the gap between the assembly and the seal bore at the top of the liner.