Manual conversion on j body

Transmissions and Rear Ends

  1. Jnfbodyguy83

    Jnfbodyguy83 Well-Known Member

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    Considering converting to stick on the doba. Anyone know what it takes to convert one to stick and what parts can I use from other mopars to make it work?
     
  2. Joe12459

    Joe12459 Well-Known Member

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    Talk to Kevin, Mirada A833. He put one in his very sweet Mirada.
     
  3. AJ/FormS

    AJ/FormS Well-Known Member

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    That's kindof a die-hard stick-man thing to do. It's a cool idea for sure but with the heft of the Doba, you will miss the Torque multiplication of the TC. To compensate, you will likely want to add some rear gear,at least one size up. Unless you go with a 3.09 low in the tranny.(BudW currently has one for sale). Next is the fact that with a 2.45 rear gear and a 2.66 low, first gear at say a shift rpm of 3200, is around 34mph. And second at 3200 is 55. And 3rd at 3200 is 75. So back down to the speed limit of say 65 =1978rpm in 4th. So basically the 2.45s kindof waste 3rd and uses 4th for nothing but cruising.
    Next let's talk about 1st gear. With 2.45s back there, the starter gear will be 2.45x2.66=6.52. This is terribly anemic,even for a 360...35mph will be 2833rpm with 27" tires.And at the shift, the Rs will drop to 2045, and this is now strictly a cruising rpm, cuz acceleration from 2000 with a 4.70 final-drive ratio will be incredibly slow. So imagine yourself keeping up in traffic at said 35mph. You will either keep it in first @2833rpm, or be shifting back and forth. Back and forth. Back and forth.
    Next try 45mph; another common speed limit.This is too high for first @3643, and a tad low for second @2630, and again in third it is a cruiser only gear @1917rpm.Accelerating from 2630 in second @45mph(a final drive ratio of just 4.70), will a 2ton brick-faced Cordoba will also be rather slow. But downshifting to first will buzz it up to 3643, and away you go.
    So what Ima saying is 2.45s gotta go.Unless you really, really, really, like shifting.
    So if you're gonna do this, it behooves you to study your driving habits, and figure out where your engine makes a reasonable good amount of torque, and put the right gear in the back to put you at the right rpm for your useage. Then it will be fun.
    Otherwise you could wake up the morning after the install with a turtle of a combo.
    As an example;
    I have a 3650 pound tank of a 68 Barracuda with a 4spd,and a warmed up hi-comp 360.It has 3.55s out back. It likes a starter gear of no less than 10/1, and it makes enough torque with that gear to annihilate 295s .My second gear makes a final drive of 3.55x1.92=6.82, and the warmed up engine can initiate a spin with that up to and beyond 50mph. This second gear puts the Rs at 35mph to 2965. At this rpm, blasting off is easy. Dropping it into third gets me 2161rpm a nice comfortable cruising speed,but I rarely do that. I usually throttle back to 2800 instead, where the speed is 33mph. This is comfortable, and the engine has plenty of pep to play in traffic.
    But now, I have a well-built engine living on the edge of too-high a compression. The way it is put together favors low-speed torque. Your 360 if stock, does pretty good with the stock cam, so unless you are planning a major rebuild, do not change the cam to a longer duration one.
    But do swap out the rear gears to at least 3.55s. More is better. Consult your driving habits. If hi-way travel is a consideration, choose well.
    Peace/out.....from a one-time,die-hard,stick-man, now at 63, not so much any more.....
     
    Last edited: Nov 25, 2016
  4. R/T Mirada

    R/T Mirada Well-Known Member

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    Hello there jnfbodyguy, any news on your manual trans ambitions? I'm just starting on my a883 conversion. Picked up an a833 and most of the related bits and pieces from a late70's Aspen, off of eBay a few months ago. I'm trying to take pics and document everything. It's going to take awhile, I'm a lot slower than I used to be.
    While surfing youtube I came across several interesting videos of a guy swaping a dodge dakota 5 speed and some of the pedal parts in to his Aspen.
    Check him out at "how to install a 5 speed in a 1976 dodge aspen" by "Mr76aspen"
    Debunking a common belief that you can't use Dakota pedals to convert FMJ's. He even used the Dakota hydraulic clutch system which will make chasing down hard to find bits
     
  5. BudW

    BudW Moderator Staff Member

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    A FMJ petal “assembly” will only fit another FMJ vehicle.
    Now with that said, it is possible that parts from another vehicle (like from a Dakota, for example) “may” fit and work together to make a complete and working petal “assembly” for a FMJ car.

    I’ve not seen Dakota petals out of the car to do a comparison, yet.
    My local Pull-a-Part does get a lot of Dakotas in – so I might extract some petals from one to do some comparisons.

    I do have a complete ’79 F-body manual petal assembly and a complete ’84 M-body automatic petal assembly – so if Dakota petal parts will help with a change-over, then great. I wonder if it actually works though.

    My plan is to put a 5-speed or 6-speed Tremec into my station wagon – using hydraulics. If Dakota does make a good source for petal parts – then it makes sense that the hydraulics might also carry over, as well – possibly.

    I can’t see the videos at work – so can’t comment about them (yet).

    The Pickup/Dakota/Jeep (New Venture) NV1500, NV2500 or NV3500 5-speed bell housing is attached to transmission - which makes installation more difficult. They made a lot of small blocks with either transmission type (NV1500, NV2500 or NV3500) in pickups, Dakotas and Jeeps – and each one is a decent transmission (GM also used a version of each one in their small/large pickups, as well).

    The NV4500 and NV5600 transmissions are large and heavy (not suitable for cars).


    Without doing a comparison – I would think the transmission crossmember will need modification for one to fit – as well as possible transmission tunnel work – but need parts to play with – to know for sure.
    They didn’t put a NV1500, NV2500 or a NV3500 in a passenger car that I’m aware of (GM or Chrysler).

    Next: to watch the video to see what they say in it.
    BudW

    I spoke to my brother and here is what he said (he has more experience on the newer stuff):
    "The NV1500 is neat looking and light, but shifter may be too far back.
    I’ve always liked the NV2500 but they had synchronizer problems – but no big deal.
    The NV1500 and NV3500 is harder to work on, in car".
     
  6. AJ/FormS

    AJ/FormS Well-Known Member

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    I think there were several different ratios of these NV transmissions, not all of which are suitable for passenger car use.
    I seem to remember reading that the Jeep ones had a separate BH.
     
  7. BudW

    BudW Moderator Staff Member

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    Very good point.
    I can find out ratio's if someone has a transmission (or two) that they are looking at.

    I am no Jeep expert so this might be correct.
    My understanding is the NV1500 to NV3500 series the Bells can be removed after removal - but not in car.
    I will admit that I'm a lot more knowledgeable on FMJ and older cars than the newer equipment (which is about the time I changed jobs).
    BudW
     
  8. AJ/FormS

    AJ/FormS Well-Known Member

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    Last edited: Oct 31, 2017
  9. BudW

    BudW Moderator Staff Member

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    If the NV1500-NV3500 transmissions will be an economical means to putting manual transmissions into FMJ’s, then I need to look in to them.

    I don’t frequent the other sites, often (FABO, FBBO, FCBO or FEBO).
    BudW
     
  10. jasperjacko

    jasperjacko Well-Known Member

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    the nv 3500 does not have a separate bell housing. 1st gear ratios are 4:1 and 3.5:1. Pretty big drop from 1-2 but if you don't need max performance and want some fun with an o.d. trans, it's a good option for a mild smallblock. I'm actually considering one for Modoba. With a 2.76 rearend, 1st gear is usable with the final drive ratio at 2.0 in overdrive. Great roadtrip mpg's