I have 428,s fitted with all the extras remap ,mathed inlets etc. Before it was mapped i didnt really notice much difference after the remap for the cams definetly improvment i am now pulling away from teg type r,s hope that helps apparantly tho c&b are a better choice. Pm sideways danny he is the expert on cams here if you can afford an extra £150 go for c&b.