4.3l V6 And Th350 In A 3a?

Discussion in 'Flat Fender Tech' started by haighfam, Jul 22, 2017.

  1. Jul 22, 2017
    haighfam

    haighfam Member

    Paradise, CA
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    Anyone had any success or suggestions on this swap, I know it may be a little long. Looks like the original family doesn't want this back after all. Bought it from their grandfather for $3500, put about a $1000 in parts to fix all the issues (springs, shocks, tires, distributor rebuild, speedometer, hubs, rebuilt ross box, tie rod ends, blah, blah ... Offered it to them for $4000 for sentimental reasons. Since I may be keeping it looking into a repower from the L134. The drive train is stock, t90, d18, OD, 5.38's.
     
  2. Jul 23, 2017
    ITLKSEZ

    ITLKSEZ Volvophilic

    Post Falls, ID
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    Friend of mine has a Chevy 350, TH350, D18 w/OD in his 2A. Rear driveshaft is short, but it's been on the road for probably 30+ years without a problem.

    With the v-6, you could even cheat it forward a little more than he could have.
     
  3. Jul 23, 2017
    haighfam

    haighfam Member

    Paradise, CA
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    Thanks for letting me know it's possible. No problem with cutting the grill to move it all forward. Will be trying to keep it stock height. Reason for this conversion is I have access to an inexpensive 4.6L from a friend I know the history on. Always wanted an automatic in a Jeep. Would make a great deer hunting rig.
     
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  4. Jul 23, 2017
    ITLKSEZ

    ITLKSEZ Volvophilic

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    I just texted my buddy, he said he'll get some pics later this week. I'll post them up when I get them. He confirmed the rear driveshaft is short. :D

    One thing though... his front driveshaft is 2-pc to clear the trans pan. Not sure if it's mandatory; the pictures will tell.
     
  5. Jul 31, 2017
    ITLKSEZ

    ITLKSEZ Volvophilic

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    Here're the pics. Front driveshaft back to front, then the rear shaft. Rear shaft is 11.5" from center to center of joints.

    [​IMG]

    [​IMG]

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    [​IMG]

    [​IMG]
     
  6. Jul 31, 2017
    47v6

    47v6 junk wrecker! Sponsor

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    next build right there.
     
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  7. Jul 31, 2017
    Keys5a

    Keys5a Sponsor Sponsor

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    Interesting 2-piece front driveshaft. I'll file that idea away for some future build!
    -Donny
     
  8. Jul 31, 2017
    47v6

    47v6 junk wrecker! Sponsor

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    Saw that in some guys build in a 2 or 3a. I believe he is in Massachusetts and the jeep is grey? Real nice.
     
  9. Jul 31, 2017
    Rich M.

    Rich M. Member

    Maryland
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    One of my favorites.
    ECJ5
     
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  10. Jul 31, 2017
    Daryl

    Daryl Sponsor Sponsor

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    With a v6 you can run any trans you want. I have been running 400 turbos behind Buick v6's for over 30 years. You can actually get a 13" driveline in a flatfender with a 225, 400, 20 combo.
     
  11. Jul 31, 2017
    pfmg

    pfmg Member

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    It's doable, the only real problem is the front driveshaft. Some guys have done it with a dana 18, By raising the whole drivetrain, essentially putting enough slant on the front DS to just clear the pan. I did not want it raised, as it causes other issues. I tried a dana 300 and with a clocking ring, and tried it in every possible position, and it just wont clear. I to ended up using a 2pc front shaft. It works fine. The whole combo is very driveable.

    1948 cj2a
     
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  12. Aug 1, 2017
    haighfam

    haighfam Member

    Paradise, CA
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    Thanks for letting me know it's do-able. I'm thinking 4.3l V6 with TH350, Dana 20 and centered 44.
     
  13. Aug 1, 2017
    ITLKSEZ

    ITLKSEZ Volvophilic

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    Just a heads up... With such a short drive shaft, the Dana 20 might be an issue with driveshaft angles.
     
  14. Aug 1, 2017
    jeepstar

    jeepstar Member

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    Why does it matter if the driveshaft is short? Does it become an issue offroading because of lack of travel on the driveshaft?
     
    Last edited: Aug 1, 2017
  15. Aug 1, 2017
    timgr

    timgr Jeepin' Nerd Sponsor

    Medford Mass USA
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    A short driveshaft is fine as long as the axle does not move up and down much, and the angle of the driveshaft is comparatively low. The shorter the driveshaft, the larger the angle for a given offset between the ends.
     
  16. Aug 1, 2017
    pfmg

    pfmg Member

    Billerica Mass
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    no issues with the short DS here, CV joint, axle inline with the shaft. 0 vibration at cruising speed, and so far no issues off road. there is not a lot of flex in these vehicles as they are, and it should only possibly be an issue when both rear wheels are at full drop,
     
  17. Aug 1, 2017
    haighfam

    haighfam Member

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    Is the Dana 20 longer than the 18?
     
  18. Aug 1, 2017
    ITLKSEZ

    ITLKSEZ Volvophilic

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    Not by much, depending on the yoke, but the output is taller. With a short shaft, a small increase in shaft height will net a large increase in shaft angle.
     
  19. Aug 1, 2017
    Daryl

    Daryl Sponsor Sponsor

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    The output of a 20 is about 4 inches higher then an 18.
     
  20. Aug 1, 2017
    haighfam

    haighfam Member

    Paradise, CA
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    I'll have to reconsider that. Will try to maintain as close to stock height as possible.
     

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