Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

what gearing in 74 k5 12 bolt

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by az88k5, Oct 26, 2006.

  1. az88k5

    az88k5 1/2 ton status

    Joined:
    Oct 14, 2004
    Posts:
    258
    Likes Received:
    0
    Location:
    Prescott Valley, AZ
    I have a twelve bolt out of a 74 k5. I need to know what the gear ratio was in this stock. does any one know? Thanks any help much appreciated

    #'s are as follows 11 2 73 Dana 18515 A3D87 41-11
    Are these 3.73's or what
     
    Last edited: Nov 6, 2006
  2. Muddytazz

    Muddytazz 1 ton status

    Joined:
    Jun 30, 2002
    Posts:
    20,073
    Likes Received:
    0
    Location:
    Salem, Or.
    pop the cover and either count the teeth or read the numbers on the ring gear
     
  3. az88k5

    az88k5 1/2 ton status

    Joined:
    Oct 14, 2004
    Posts:
    258
    Likes Received:
    0
    Location:
    Prescott Valley, AZ
    The pinion fell in and I can't turn the ring gear or I would, and its not worth pulling the axles and carrier. thanks for the info though
     
  4. 84PolarBear

    84PolarBear Registered Member

    Joined:
    Feb 19, 2002
    Posts:
    86
    Likes Received:
    0
    Location:
    San Francisco
    It should be 3.73
     
  5. Muddytazz

    Muddytazz 1 ton status

    Joined:
    Jun 30, 2002
    Posts:
    20,073
    Likes Received:
    0
    Location:
    Salem, Or.
    not necessarily....i've seen 3.08's, 3.73's and 4.10's all being stock for that yr
     
  6. pauly383

    pauly383 Daddy383 Staff Member Moderator

    Joined:
    Jul 22, 2001
    Posts:
    16,217
    Likes Received:
    1
    Location:
    Mesa , Arizona USA
    Bit of trivia , 3.08's in a 12 bolt are actually 3.07 and a bunck of decimal places :wink1:
     
  7. Muddytazz

    Muddytazz 1 ton status

    Joined:
    Jun 30, 2002
    Posts:
    20,073
    Likes Received:
    0
    Location:
    Salem, Or.
    paul, on my old 1/2ton stuff (D44/12b) the numbers came out to 3.07 on my 44 and 3.08 on the 12b :dunno:
     
  8. imiceman44

    imiceman44 1 ton status

    Joined:
    Aug 5, 2002
    Posts:
    15,160
    Likes Received:
    1
    Location:
    Sacramento, CA
    If it was auto it should be 3.08
    If it was a manual they had the choice 3.73 and 3.08
    Although you could always have custom gearing, but standard for 74 was those numbers.
     
  9. Cmoe

    Cmoe 1/2 ton status

    Joined:
    Feb 19, 2000
    Posts:
    2,884
    Likes Received:
    0
    Location:
    Mesa,AZ
    My 74 came with 4:10's.... so you'll need to pull the cover and check manually....
     
  10. imiceman44

    imiceman44 1 ton status

    Joined:
    Aug 5, 2002
    Posts:
    15,160
    Likes Received:
    1
    Location:
    Sacramento, CA
    Do you know for a fact it was stock?
    Was it with a tow package?
    What engine did it have? the 400 SBC came with higher gears too.
     
  11. Cmoe

    Cmoe 1/2 ton status

    Joined:
    Feb 19, 2000
    Posts:
    2,884
    Likes Received:
    0
    Location:
    Mesa,AZ
    1974 K-5, Trailer Special, 350/350/203... and yes it's on the RPO as 4:10's....
     
  12. imiceman44

    imiceman44 1 ton status

    Joined:
    Aug 5, 2002
    Posts:
    15,160
    Likes Received:
    1
    Location:
    Sacramento, CA
    Yeah I forgot about special editions like trailer, HD, tow package, those came with different gearing, but they were noted, badged as such.
    Most production lines were the same as described above. :D
    I had lots of spec sheets from the dealers in the mid 70's that is why I know a little bit about this.
    They had a little more info than the sales broshures.
    :wink1:
     
  13. nau81blazer

    nau81blazer 1/2 ton status

    Joined:
    Mar 6, 2004
    Posts:
    329
    Likes Received:
    0
    Location:
    Cincinnati, OH
    Did you happen to fix this yet? I really need some 3.73 or lower that I can just bolt in...Thanks.

    Adam
     
  14. az88k5

    az88k5 1/2 ton status

    Joined:
    Oct 14, 2004
    Posts:
    258
    Likes Received:
    0
    Location:
    Prescott Valley, AZ
    No I'm not going to fix it, I don't have the yoke for the pinion.
     
  15. az88k5

    az88k5 1/2 ton status

    Joined:
    Oct 14, 2004
    Posts:
    258
    Likes Received:
    0
    Location:
    Prescott Valley, AZ
    heres the #'s off the ring gear

    11 2 73 Dana 18515 A3D87 41-11 389

    Are these 3.73's or what????
     
  16. 1BEATK5

    1BEATK5 1/2 ton status Premium Member

    Joined:
    Dec 15, 2005
    Posts:
    2,735
    Likes Received:
    32
    Location:
    beaverton orygun
    41-11 means 3.73 41 ring gear teeth divided by 11 pinion tetth gets the answer
     
  17. imiceman44

    imiceman44 1 ton status

    Joined:
    Aug 5, 2002
    Posts:
    15,160
    Likes Received:
    1
    Location:
    Sacramento, CA
    Yep 3.73 and this is the original for your 74, built november 73.
     
  18. Gorillajeep

    Gorillajeep 1/2 ton status Premium Member

    Joined:
    Sep 7, 2006
    Posts:
    238
    Likes Received:
    1
    Location:
    Myrtle Beach, SC
    What gears did the 400 SBC have? You brought it up. . . .
    James
     
  19. imiceman44

    imiceman44 1 ton status

    Joined:
    Aug 5, 2002
    Posts:
    15,160
    Likes Received:
    1
    Location:
    Sacramento, CA
    Well supposedly 3.73 or optionnal 4.10 no 3.08.
    :confused:
    As for my "original for you 74" I meant gears said 11-73 so late 73 for a year model 74 so most probably still the original gears.
    :D
     

Share This Page