Need slight mod or just plug and play?
just adapters to bolt on from the caliper mounting points to the mounting point of the stock caliper on the hub
but the adapters were simple no welding or shaping of the metal so the metal keeps its strength
also the disks were re-drilled to suit the 4x114.3 stud pattern
Fitted fine under my 16" Enkei wheels
owner of the shop told me Subaru 4 pot is a much easier fit to Lancer than other budget 4 pot options such as Skyline R32 and Toyota Vigo pickup.
hope that helps