 speedometers became standard in the IROC-Zs and Z28s with tuned port injected engines while the carbureted Camaro models and 2.8 liter V6 retained the 85 m.p.h.speedometer.Other changes included a Camaro convertible that was introduced for the first time since 1969 as a regular production option.Available on the Sport Coupe, LT and IROC-Z, the conversion was performed on t-top equipped Camaros by American Sunroof Company (ASC).