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Discussion Starter #1
Hello,
I have a '63 Jeep J300 (126" wheelbase) that I intend to use mainly for moving stuff around, very light offroading, and to occasionally tow my 4400 lb '66 Olds Toronado. The truck currently has a Buick 350, T18/D20 and late 70's J10 Dana 44's. It also has a saginaw P/S box and power brakes.

I have a 4BT that after I finish my current projects (funny, uh?) I want to put into the truck, to have an economic, medium duty truck that can be driven all over the place.

A set of D60/D70 from a 1990 Dodge W350 diesel have fallen into my lap (figuratively :smile: ) and was looking at the possibility of putting these in my truck. Given that I don't plan on going larger than stock tires (I want to keep it stock looking) this is way way overkill, but the larger brakes would be nice to have when towing. My current pair of D44's is better sized for what I want, but I really dislike having a semi-floater rear. Would I be better off selling the D60/D70 and getting a pair of J20 axles (D44HD/D60, also for the stock look I want - I appear to have a fetish for stamped steel rims)?
What do you say?
Mikel

 

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Nice lookin truck. Looks like mine has a cousin.....check out J10 in the build up section.

As for axles. The power a 4b makes can be handled by d44 axles. HOWEVER....you intend on towing which means greater strain on the rear axle and more braking demand on the front. AND depending on how much offroad you plan on doing and how much you have done will determine how addictive it is to you. Basically, overbuild so you wont be sorry and or broken later.

I you suggest at least a 60 rear 44 front. But if you already have a set of one tons......I would throw them in. Then whatever purpose your rig ends up fullfilling, your axles arent the limiting or weak link. You can build your motor up, so whatever performace wise down the road get done, your already ready to channel the power. Also helps resale value shoulg you unfortunatley end up in that position.

My humble opinion
austin
 

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Discussion Starter #3 (Edited)
Hello Austin,

You have a VERY cool truck (although I'm a bit biased :grinpimp: ). Do you have more pictures??

My 4BT has the old style pump, so it won't be making obscene amounts of power. I'll be satisfied if I can bump it to 150HP and 350ft-lbs. I was a bit concerned that the extra weight from axles that are WAY oversized for my needs would hurt my fuel economy. What kind of MPG have you been getting in yours with the 4.10's? How do you like it performance wise?

My initial plans for the truck were to go with a 6BT, so I guess if ever decided to do that, the truck would be better suited.
Thanks,

Mikel
 

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My 4b isnt in yet. I was getting 18 mpg in the city with 35s and a 6.2/TH400! I expect great things in the way of mileage!

At bare minimum, I think a heavy duty rear would be best (D60) for towing if nothing else. By the time you do that, weight difference of a Dana 44 vs a Dana 60 would be little.......for a Cummins. There is nothing wrong with a 44/60 combo and selling the one tons more mods or other parts.....Jeeps seems to need something all the time. (My door panels fell apart so its diamond plate this time:smokin: ). Unless you run larger tires, lock your axles, and go offroad, a good 44 will hold the power.

If you do go 6B... definately a D60 front just to support the weight.

Ill get some pic of the truck on 35s as it awaits its transplant! Should be soon

Thanks
Austin
 

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Discussion Starter #5
Austin, is that a Ford D60 you have up front?
 

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It is. There is a divorced Ford NP205 to switch the otherwise Chevy/GM drivetrain to driverside drop
 

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Mikel, the weight differences between axles is more or less irrelevant for the motor's purposes. 60/70 and don't look back!!! :)

The front will be the relatively heavier one, but not heavy enough to impact mileage in a meaningful way. Maybe like having a passenger. To get you thinking about it another way, the torque of my 454 in the work truck took a mere .75mpg mileage hit, going from empty to loaded w/5k worth of stuff. And since I was going into a good headwind on the loaded trip, I'm not sure if it noticed the WEIGHT at all. The Cummins should react in a similar manner.

and yeah, if you ever go with a 6bt, you will NEED the 60 up front. It is f'ing heavy.
 

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I would put in the 60/70 combo since you have them,but the stockers would be fine as long as you only a DD,light towing.

As a side note *

some of those dodges had the rare dana 61 ,there will be a stamped f-60 or f61 ,but if you have the 61 that won't matter for what you want to do with the truck!

Scott
 

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Discussion Starter #9
Hello,
I'm aware of the Dana 61 issue, but I'm not overly concerned. I would just need a spacer for the ring gear in order to run D60 pinion/ring gears.

Does anyone have an idea of how much heavier a D60/D70 combo would be compared to a D44HD/D60 set? 300-400 lbs?

Thanks,
Mikel
 
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