SPEEDOMETER GEAR CHARTS 1975 77 CORVETTE 4 SPD TIRE 3 08 RATIO 3 36 RATIO 3 56 RATIO 3 70 RATIO 4 11 RATIO SIZE DRIVE GEAR DRIVE GEAR DRIVE GEAR DRIVE GEAR DRIVE GEAR 361002 361002 361002 36100Z 361002 GR 70 15 Driven A Driven B Driven A Driven C Driven D Adapter E Adapter E Adapter E Adapter E Adapter E 367002 is a secnnd design drive gear identified by speeda adapter 6250705 is the ist design DRIVEN SLEEVE GEAR TEETH COLOR ASM CODE ADAPTER A 3987919 19 Natural 345215 B 3987918 18 Brown 345215 C 3987920 20 Blue 345215 D 3987922 Z2 Silver 345215 iGM PARTS DIVISION GENERAL MOTORS CORPORATION CHEVROLET 14 4 000 GROUP 4 6 C REV 5 80