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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: blublazn86 on September 23, 2011, 12:41:09 pm
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I have recently purchased an 87 2wd r10 truck with a 700R4 trans and I was curious as to which gears were in the rear diff so i pulled the cover and did the counting and division thing and what I came up with blew me away....it has a 3.25 gear ratio!!! Is that a common gear or not?? I've seen 3.73 3.42 but never a 3.25 gear in one. Anyone have any insight to this??? Please help!!!!! Thanks
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The rear gear options for the 87 with a 700r4 were 3.23:1, 3.42:1, 3.73:1 with an option of 4.10:1, from what I can find about them.
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did you count the teeth on the pinion and ring gear? If you pulled the pumpkin and it is a GM set, the numbers are marked on there you just have to divide. There wasn't a 3.23 offered on 1/2T trucks, only 3/4T tucks.
For an 87 R10 with the 700R4 and 305 or 350 the options on axle ratios were 2.73 (most had this), 3.08 or 3.42. You couldn't get 3.73's from GM on a 1/2T with the 700R4.