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I am planning to put a 4BTin my Jeep, but I really don't want to change my transmission. I know the 904 is a marginally rated unit, but I just rebuilt it with a shift kit, kevlar bands and a deep sump, so I'm pretty sure it could handle what I wanted to do with it.

Since whatever I would swap in would most likely require an adapter to connect to my Dana 300 T-case, plus the cost of a different transmission, I believe leaving the 904 in there, if possible, would be the way to go. This jeep is mostly driven on the road, and only lightly wheeled when off-road.

Right now, I have a rebuilt 258, bored .030 -over, with a 4.0 head and GM TBI. It's okay, as far as power goes, but 15 MPG makes it too expensive to drive anywhere, and I like the idea of being able to run veg oil, stove, oil, waste oil, or whatever else I decide to throw at it.

I would certainly appreciate any ideas, as far as bell housing adapters and flex plates.

Thanks!
 

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I been wrong before but in this case I don't think there is such a thing. You could run a cummins specific 727 with correct output and extension and still bolt onto your d300 tc. 1st gen dodge flywheel housings are available and fairly cheap. iirc the d300 is the round bolt pattern?
 

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I would not use the 904, I understand your thoughts on the fresh rebuild but it is all wrong for a diesel. Considering your current economy, and the cost of a 4bt swap I would stay with your current engine trans setup.
 

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I would not use the 904, I understand your thoughts on the fresh rebuild but it is all wrong for a diesel. Considering your current economy, and the cost of a 4bt swap I would stay with your current engine trans setup.
This.

$4000 (minimum) would buy 1500 gallons of gas. Do you realize it would probably take 5 years to recoup your investment?
 

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This.

$4000 (minimum) would buy 1500 gallons of gas. Do you realize it would probably take 5 years to recoup your investment?
hey, Lee. :D

I'm just doing the math quick here, and not counting the cost of rebuilding the 454 that's already in MY truck, or the $3000 I paid for my Cummins stuff a few years back. :(

gas: $2.70/gal 10k mi @ 8.5mpg = 1,176gal @ $3,176.00
diesel: $2.80/gal 10k mi @ 15mpg(min :D) = 667gal @ $1,866.00

So even with the economy, it would take me, at these rates, about 2yrs to recoup my investment. :D
 

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hey, Lee. :D

I'm just doing the math quick here, and not counting the cost of rebuilding the 454 that's already in MY truck, or the $3000 I paid for my Cummins stuff a few years back. :(

gas: $2.70/gal 10k mi @ 8.5mpg = 1,176gal @ $3,176.00
diesel: $2.80/gal 10k mi @ 15mpg(min :D) = 667gal @ $1,866.00

So even with the economy, it would take me, at these rates, about 2yrs to recoup my investment. :D
hey! dont forget the oil changes and little stuff like $100 belt tensioners, air and fuel filters... etc..... and a 6b is a cheaper swap than 4b.....
 
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