I have a 88 1500 with a 4.3L and a 5spd manual. What was the tipical gear ratio of this combo? I have no ident tag on rearend or door tag. Thanks

3.23 or a 3.43 gear, If you call a chev dealer, they can run a VIN check and let you know, this is a free service

Check in your glove compartment for the option codes. Look for one of these codes: GH0 AXLE REAR, 3.54 RATIO GH2 AXLE REAR, 2.29 RATIO GH3 AXLE REAR, 2.77 RATIO GH4 AXLE REAR, 2.92 RATIO GK9 AXLE REAR, 4.63 RATIO GL3 AXLE REAR, 6.17 RATIO GM1 AXLE REAR, 2.59 RATIO GM3 AXLE REAR, 3.45 RATIO GM8 AXLE REAR, 2.56 RATIO GQ1 AXLE, STD RATIO GS4 AXLE REAR, 3.70 RATIO GTY AXLE, WIDE TRACK GT4 AXLE REAR, 3.73 RATIO GT5 AXLE REAR, 4.10 RATIO GT7 AXLE REAR, 3.33 RATIO GT8 AXLE REAR, 4.10 RATIO GU1 AXLE REAR, 2.41 RATIO GU2 AXLE REAR, 2.73 RATIO GU4 AXLE REAR, 3.08 RATIO GU5 AXLE REAR, 3.23 RATIO GU6 AXLE REAR, 3.42 RATIO GV2 AXLE REAR, 5.83 RATIO GV4 AXLE REAR, 3.36 RATIO GV8 AXLE REAR, 2.72 RATIO GW4 AXLE REAR, 3.31 RATIO GW6 AXLE REAR, 3.27 RATIO GW9 AXLE REAR, 2.93 RATIO GX3 RATIO,TRANSAXLE FINAL DRIVE 3.33 GYS RATIO TRANSAXLE FINAL DRIVE 3.65 G44 AXLE REAR 3.07 RATIO G5O SPRING REAR, HEAVY DUTY, VAR 1 G51 SPRING REAR, HEAVY DUTY, VAR 2 G52 SPRING, RR, 15000 LBS G60 SPRING REAR, AUXILIARY G66 LEVEL CONTROL, MAN, AIR G67 LEVEL CONTROL, AUTO, AIR G69 LEVEL CONTROL, AUTO, AIR, HD G72 AXLE REAR, 2.14 RATIO G75 AXLE REAR, 3.62 RATIO G80 AXLE POSITRACTION, LIMITED SLIP G87 RING GEAR, 8.50 INCH G89 RING GEAR, 7.50 INCH G92 AXLE REAR RATIO, PERFORMANCE G9S AXLE REAR RATIO, ECONOMY

You can only in general run codes with a VIN on about 90 and up models. Can't do it with older vehicles. Needs a 16 digit VIN.