Because many of the bits and pieces that went into the 4-4-2 package could also be ordered separately, it's important to know how to make sure you're looking at the genuine article. The eighth code of the VIN should be a 9, indicating the high-output 307, and there should be a W42 code on the RPO sticker located under the trunk lid. Under the hood should be a dual-snorkel air cleaner with a chrome lid, while dual exhaust outlets should be out back. On 1985 and '86 cars, there should be a cutoff switch under the accelerator pedal, to kill the air conditioning compressor under full throttle. The passenger side of the transmission should be marked with the code OZ on 1985 cars and KZ in 1986 and '87. Finally, if you're looking at a 1987 car, there should be a speedometer that reads to 120mph, rather than 85mph.