will it go? i seen people using the st head on the silvertop bottom so surely it will go the other way round, what would be involved in the swap? also whats the main differences between the black top and silvertop zetecs? whats interchangeable between the 2? im thinking of building up a stronger zetec turbo lump using as much from my silvertop as i can so would like to keep the sump, head for my turbo cams and springs, turbo, clutch and flywheel etc