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rear end questions

Discussion in 'General Chevy & GM Tech Questions' started by racinea64, Aug 10, 2012.

  1. racinea64

    racinea64 New Member

    hows it goin guys i'm new to this fourm.

    so i have an 87 GMC cabilero and i've been lookin for a posi unit so i can actually get somewhat of a good launch at the drag strip.

    yesterday i came across a chevy 1500 4.3 vortec pickup and the salvage yard i'mnot sure of the year cause the doors were gone but i'm asuming that it was a 96 or newer. but anyway i spun the pasinger side tire and clunk the posi ingaged. but thats not the issue. I have no idea wether or not it has an 8.5 in ring gear. it's a 10 bolt and i stupedly forgot to look at the id tag.

    and how do i tell if it has 28 splines of 30 spline axles?

    also my car has a fore link suspension system that the upper control arms connecto to the top of the pumpkin case so i would need to weld the upper control arm mounts on. is the pumpkin case on that diff cast iron? and if so how could i attach the upper control arms so they wont come flying off on a hard launch?

    p.s. i know this rear end is too wide, i've shortened axle widths before but i've always worked on leaf spring trucks never anything with a fore link

    thanks for any info you can give me

    Neil
  2. Boonduff

    Boonduff Member 3 Years 100 Posts

    You're barking up the wrong tree. GM used the Eaton G80 Gov-Loc in 1973 and newer trucks. This diff is not a good choice for a vehicle used on the dragstrip. It has many small parts inside, and they have been known to chuck those small parts with normal street use. On a strip it won't last long. You need a clutch type limited slip like the Eaton Posi or the Auburn

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