For Chevrolet Astro V6 4.3L OHV Naturally Aspirated Petrol Upper 1996-2005. For Chevrolet Blazer V6 4.3L OHV Naturally Aspirated Petrol Upper 1996-2005. High Strength: The intake manifold design has excellent strength to ensure that it can withstand the automotive engine vibration load, throttle and sensor inertia force load, intake pressure pulsation load.