the LB9 305 with the G92 (Performance Axle Ratio) option were made in 1985. The G92 option upgraded the rear axle gear ratio from 3.23 to 3.42. Also new for 1985, all Camaros featured refreshed noses, and new deeper valances and front spoiler for the Z28 and the newly introduced IROC-Z. The speedometers no longer had the unique double-pointed needle that simultaneously read mph and km/h: they were replaced by conventional single-pointer units. For 1985 a (1C5) RPO California IROC-Z was also made, Chevrolet's California Marketing Group came up with the idea and it was for sale in California only. A total of 250 black and 250 red examples were produced. They were all equipped with the 5.0 TPI LB9 engine and TH700-R4 automatic transmission. All came equipped with the IROC-Z fog lights, wheels and ground effects, but with the base Camaro's hood (no louvers), rear decklid (no spoiler), and no exterior decals. 1986 A newly required Center High Mounted Stop Lamp (CHMSL) was installed on the Camaro. 1986 was the only year to see this attached to the outside hatchback glass on base model Sport Coupes, Z28s, and IROC-Zs except for 1987 base models that did not have a spoiler. This was the final year for the L69 5.0 305 HO 4-bbl option, of which 63 were built for racing in Canada's Player's series and 11 for public sale, making a total of 74. The 2.8 L V6 was now the standard engine in the base model, replacing the 2.5 L I-4 model. The 305 TPI LB9 horsepower rating dropped from to in the IROC-Z models. All V8 engines received a new one-piece rear main seal. Braking performance was 139 feet from 60mph. 1986 would be the final year for the Berlinetta trim level. 1987 The 350 TPI engine with automatic and 305 TPI with 5-speed manual transmission were available for the first time in the IROC-Z. The new 350 (RPO code L98) was available only in the IROC-Z with an automatic transmission. The TPI 350 motor was visually distinguishable from the TPI 305 as the bumper cover decal had "5.7L" added to the "Tuned Port Injection" decal. It can also be determined by checking the VIN (8th character, F=305, 8=350). The 305 TPI equipped with automatic transmission came with 190 hp, while the Manual 305 TPI got a rating. The 350 L98 gave a boost to 225 hp