Complex sentence: Vistas made before 1992 were built on either GMC or a Chevrolet chassis, equipped with a Detroit Diesel 8.2 liter engine.
Split into simpler sentences: Vistas made before 1992 were built on either GMC or a Chevrolet chassis. The Vistas built on Chevrolet Chassis were equipped with a Detroit Diesel 8.2 liter engine.