That's because the Olympian's design was based on the Titan. The
Titan was launched in 1975. It came with an integral bodywork and
proved not to be very popular with the operators who prefer to have
standing connections with their specific body builders. Hence, a
new project, codenamed B55, was launched to design a new model with
advanced features of the Titan. The project was unveiled at the
1980 Commercial Motor Show and the chassis was given the name
'Olympian'. The Olympian turned out to be Leyland's most successful
model with more than 30,000 units sold worldwide. In fact, if not
for the Olympian, Leyland would've been ruined well bofore the
Volvo takeover in 1985.