sentences:  The Astro and Titan would become the final trucks of the type assembled and marketed by General Motors, following the 1981 exit of Chevrolet from heavy truck sales and the 1986 creation of the Volvo GM joint venture.The Chevrolet Titan and GMC Astro were assembled at Pontiac Truck & Coach/Truck & Bus (Pontiac East Assembly) in Pontiac, Michigan, with the final GMC Astro produced in 1987.In 1959, GMC introduced its Class 8 cabover trucks, replacing the previous "Cannonball" fixed-cab COEs.