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373 Gears

Discussion in 'Early CJ5 and CJ6 Tech' started by ib4classics, Nov 21, 2009.

  1. ib4classics

    ib4classics Member

    I picked up a nice used windshield (69) and Dana 44 rear (69 with 373 gears) and what is probably a Dana 27 front (69 with 373 gears).
    I want to replace my current 61 538 axels with the 69's.
    I am running the stock F Head motor and running gear.
    I will not be doing much if any serious off road driving.
    Do you think the 373 gears will provide reasonable street driving with the F head as far as power goes?
    Thanks
    John
     
  2. timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    I expect you will not be happy with the 3.83s. Your top speed will probably go down, because you won't have enough power at lower RPMs to overcome wind resistance at highway speeds. Certainly acceleration will be a lot less because of the gearing change.

    A better approach would be to add a Warn/Saturn overdrive. This would give you an effective axle ratio of 4.04 for the highway and you'd keep the acceleration provided by the 5.38 gears.
     
  3. kaiser_willys

    kaiser_willys Well-Known Member

  4. windyhill

    windyhill Sponsor

    3:73's are terrible. Keep the 5:38's and look for an overdrive.
     
  5. nickmil

    nickmil In mothballs.

    Years ago we did that for a customer with a Scout 80 or 800. 152 4 cylinder. Went from 4.27's to 3.73. That thing was no fun to drive after that. 3rd gear was like overdrive with the power loss. Kind of apples to oranges as the Scout is heavier but the 152 has more power torque than the F head so kind of a decent comparison.
     
  6. Chilly

    Chilly Active Member

    With 3.73 I'm dang glad I have a V8. The stretch from 2nd to 3rd on my T15 will kill a 4-cylinder. With the torque of a V8 it's OK, though.
     
  7. ib4classics

    ib4classics Member

    Thanks to all for the feedback. I was considering a different engine anyway and I would rather have the 3.73's for my purpose.
    I'll do more research on the V-6s I think and see what I come up with.
     
  8. 66cj5

    66cj5 Jeep with no name

    the :v6: and 3.73 gears are a good combo, although the 4.27's are better with an OD.
     
  9. oldtime

    oldtime oldtime

    Not saying you can't run the OD with 4.27 ratio but....

    According to Willys Motors Inc.this is recommended equipment for 5.38 and 4.88 to 1 axle ratios only.

    I certainly agree with Willys Motors on this recommendation
     
  10. JeepPower

    JeepPower Hopeless Gearhead


    ditto-- x10!


    I love my 5.38's around town-- rowing through the gears is great-- the 134 pulls happily in each of them. The overdrive is the gravy-- I can easily do 60 on the open road.

    Your tire size can do alot to offset the deep gears as well. I'm running 215-85-16's.


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