SPEEDOMETER GEAR CHARTS 1975 SPEEDO GEAR USAGE CHART B GAR mya ngnv n GEAR V GEAR ADAPTER A 8628838 10 Purple 3987919 19 Natural 345215 H 3950354 9744 Y B 6261785 10 Purple 3987918 18 Brovsm 345215 J 3905497 8000 T 3987921 21 Red 345215 K 6273218 8974 B 3987920 20 Blue 345215 3987922 22 l Silver 345215 1978 SPEEDO GEAR USAGE CHART B CAR l 4 5 4 V 7 c Fm 15 r m 4 A HI Gmc 15 cava 16 A IIE ma 1s IIIIII GR70 15 HR78 15 III HR70 15 uma 15 E IEIIIIE IIIIIIII FR78 15 GR70 l5 GR78 15 273 MGS IIEII IEIIEIE IEIIII J GR70 15 GR7B 15 3 08 B Q l Ham 1s HR78 15 IIEIEI 1 V A j GM PARTS DIVISION GENERAL MOTORS CORPORAT 0N CHEVROLET 10 4 000 GROUP 4 4 C REV 9 78