For 1978 and 1979, the station wagon from the discontinued Astre series was added to the Sunbird line, as seen here in this 1979 Pontiac Sunbird Sport Safari Station Wagon example. They continued to use the same front fascia as the Astre with Sunbird badging. The 2.3 L engine was simultaneously discontinued.
For the 1979 model year, the Chevrolet‘s 5.0 L (305 cid) V8 engine was made optional in the notchback and hatchback, while the Sunbird Safari wagon continued for its final year with a revised vertical styled grill. The 1979 engine options included the 305-V8, 3.8L-V6 and an 2.5L-I4. (image source: coconv)