I have a 1986 Chevrolet Camaro IROC-Z that I drag race about once a week in the summer. The motor (350) has 70,000 miles on it. I think GM recommends 10W30 for it (don't have the manual). I read the advantages of synthetic oil, but I don't drive this vehicle in the winter and I probably wouldn't extend my oil change intervals due to the car's application. The Camaro isn't strictly a race car; I drive it moderately in the summer, too. The last oil change I put in Mobil 1 full synthetic, but I think I might have done so unnecessarily. Should I switch back to dino?