backgrounds changed from black to silver. Dash badges on the IROC still read "Z28" on top and "IROC-Z" below. The VIN code 8 is the engine code for a real TPI 5.7L IROC. 1989 The 1989 model year signified the return of the RS designation (last used in 1987 on a limited-edition California only model). The Rally Sport was now the base model featuring body ground effects mimicking the IROC and the previous Z28 but with the 2.8 V6 fuel-injected engine as standard with the 305 as an option. The raised rear spoiler that became available in 1988 on the base coupes was short-lived and done away with for this year. The engine ratings carried over from '88 with the addition of IROC-Z Coupes had a new dual catalytic converter exhaust option N10 that was standard with the G92 option only available on the 305 TPI motor with a manual transmission and the 350 TPI only available with the TH700-R4 automatic. 1989 was also the last year any third-gen with the B2L RPO 350 TPI L98 engine could be ordered in combination with the CC1 RPO removable T-Top roof panels. Power ratings also varied in the 305 from 170 hp (standard RPO L03) to 230 hp (RPO LB9 with manual transmission and RPO N10 dual catalytic converter exhaust) and a boost to 240 hp for the 350 with RPO N10 respectively. IROC-Zs with the TPI 350 had the 2.77 rear axle ratio as in the previous year, but the optional RPO G92 Performance Axle package modified the ratio to 3.27 for the TPI 350, and 3.45 for the TPI 305 with manual transmission. RPO G92 also included the aforementioned dual-converter exhaust; 4-wheel disc brakes (RPO J65); engine oil cooler; P245/50ZR16 Goodyear Eagle unidirectional tires; a speedometer; and a tachometer with a 5,500 rpm redline. A total of 1,426 IROC-Z coupes were equipped with the Performance Axle package in 1989. To take an IROC-Z coupe to the maximum performance extreme in 1989, when the G92 Performance Axle was ordered with no air conditioning (C41), RPO code 1LE was automatically triggered. This included extra equipment intended to make the IROC-Z more competitive in SCCA Showroom Stock road racing events: larger rotors with 2-piston aluminum calipers from PBR; an aluminum driveshaft; a special baffled fuel tank; specific shock absorbers; and stiffer suspension bushings. The fog lamps were also deleted. The 1LE was simply