My box ( ex VX SS) did not come with screw out bung
The B&M shifter required some filing of mounting holes but not much. Make sure the mounting bolts dont bottom out.
The model mike used dosent seem to have clearance problems I experienced with housing. Our gear boxes are different externally and maybe the ratios are different also.
I also cut threaded section off shifter to get it shorter then glued on custom made knob. Dont laugh at glue. Couldnt get knob off with 18" pipe wrench. Came off with heat, the glue melted made gas and knob lifted off. So did my head dont know what was in that glue.
Phil