Complex sentence: While largely based on the 308 GTB and GTS respectively, small modifications were made to the body style and engine, including an increase in engine displacement to 3.2 L (3185 cc).
Split into simpler sentences: While largely based on the 308 GTB and GTS respectively, small modifications were made to the body style and engine. The engine displacement bumped up to 3.2 L (3185 cc).