I have been looking to see what spark plug to use for my 1986 Mariner 75 hp 4 cylinder. I found that the number for NGK is BUHW-2 which it currently has installed. This is a surface gap spark plug. I have been doing some looking and some are saying that surface gap is better for long WOT runs and the "J" type are better for slower speeds. I run alot of shallow water so I am usually running fairly slow. Can i use a J type plug without clearance issues in this engine? Or do i stick to the surface gap plug? Thanks!