A further order saw 182 O305s bodied by with the Galvastress Mark 3 body enter service between August 1981 and October 1983 with one built with a prototype Mark 4 body. The revisions to the body were minor, and the most noticeable were a return to four-piece sliding windows to improve ventilation and to 203mm high route numbers at both the front and rear after the 127mm examples proved unpopular. The Mark 3 body was also used on 30 O305G articulated buses. A trial unit was delivered in September 1981 followed by the production units between September 1983 and May 1984.