3 SPD TRANSMISSION 4 337 GEAR Transmission Speedometer Driven NOTE For application see speedometer gear chart SPEEDOMETER GEAR CHART 1971 2 3 DRIVE GEARS NOTE To order speedometer gears and parts transmission type rear axle ratio and tire size must be known PART NUMBER COLOR NUMBER OF TEETH 6661666 66 66 6 66 DRIVEN GEARS 3987918 Brown 18 3987919 Natural 19 3987920 Blue 20 3987921 Red 21 3987922 Silver 22 REAR AXLE 4 337 GEAR 4 343 GEAR RATIO REAR TIRE SIZE SPEEDO DRIVEN SPEEDO DRIVEN 71 3 077 E78 14 F78 14 3987919 72 3 083 E78 14 F60 15 3987920 6261794 72 3 083 F78 14 3987919 6261794 73 3 083 G 70 14 G78 14 3987919 6261794 73 3 083 H78 14 3987918 6261794 71 3 308 E78 14 F78 14 3987921 72 3 31 E78 14 F78 14 F60 15 3987921 6261794 71 3 364 F78 14 F78 14 3987921 72 3 364 E78 14 F78 14 F60 15 3987921 6261794 73 3 42 G70 14 G78 14 3987921 6261794 73 3 42 H78 14 3987920 6261794 1974 ALL w 3 SPD DRIVEN SLEEVE GEAR TEETH COLOR CODE ADAPTER CODE ASSY A 3987920 20 Blue F 3950354 H B 3987921 21 Red G 326569 I C 3987922 22 Silver D 3987919 19 Natural E 3987918 I 18 Brown Y j GM PARTS DIVISION GENERAL MOTORS CORPORATION SPR NT 57 4 337 4 337 4 4 REV 4 81