Abstract: A seal gland comprising an annular seal engaging surface and, radially outward of the surface, a mounting portion comprising one pair of bolt positions comprising radially elongated slots equidistantly spaced about the surface and, equidistantly spaced between said positions of said first pair, a second pair of bolt positions each comprising a plurality of detents radially spaced from each other at predetermined radial positions, whereby bolt holes may be accurately drilled, as required, at a selected one of said detents of each position of said second set.