Can someone tell me what 12-bolts will bolt up to my 69 K5?

Discussion in 'The Garage' started by chevy_muscle, Jan 6, 2005.

  1. chevy_muscle

    chevy_muscle 1/2 ton status

    Mar 16, 2004
    Likes Received:
    Murphy, tx
    I'm wondering what donor trucks I can get a 12-bolt from that will bolt right up to my '69 blazer.

    I'm looking for a posi rear end and mine is open.

    Here's a link to my wanted post:
  2. fatbob

    fatbob 1/2 ton status

    Jul 3, 2003
    Likes Received:
    Phoenix, Az
    The factory POSI would probably be the gov-loc which does not have a good reputation. Another issue would be to keep the gearing the same in both the front and rear axles. Since you were lucky enough of get an open 12 bolt , you can just buy a lockrite {$220 at jegs}, put it in and your set.:D
  3. R72K5

    R72K5 Banned

    Mar 5, 2001
    Likes Received:
    central IL
    if its 4x4 k5 69-72 then only 72 older 4x4 or any years rear 1 ton axles will fit

    69-72 4x4 are 40" spring perch centers

    these are 40 centers too:

    - 1 tons(C/K-30's) '60`s and up years(k-30 did not exist til 77)
    -'69-72 k5's(4x4's only)(all 69's were 4x4)
    -68-72 longhorns(C-20 C30 trucks with fleetside bed, these were built on 1 ton chassis)
    -'69-70 9 foot steps(these were built on 1 ton chassis also)

    shock mounts changed 73-up. but thats no biggie, yank yank

    range of ratios you will find under the above models- except 69-72 K5's in which were 3.07/3.73:

    no gov lok until in the 70s sometime, the 67-72 trucks were good old reliable strong clutch pack limited slip :D you can still find them around although most all of them are with 3.07 ratio,

    dana 60 were powrlok
    eaton 52 and 72 and 110 were no-spin i believe

    and there was one more posi unit under gm trucks i forgot name and applications, id have to go and look

    good lcuk

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