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Discussion Starter · #1 ·
Hello. I have a 1992 D250 regular with a 5spd manual trans. I'm looking into converting it from a 2wd into a 4wd and was wondering if anyone could give me some advice. I want to keep it a 5spd and I have a set of Dana 60's that I'm going to put under it. What I want to know is what 4wd manual transmission and transfer case should I look for or use in converting it? If you could help I'd be very greatful

Thanks
 

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you options are the 4wd getrag and a 29 spline np 205 transfercase thats what the w- series trucks have or you could keep your 2wd tranny and divorce the transfercase
 

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Discussion Starter · #3 ·
Thanks. What would a good gear ratio be for the axles for street/towing use (in Michigan snow and whether) and still get a good mpg with the getrag? I'm pretty sure the axles I have are from a gas truck and I dont think the ratio would be any good to match with the cummins, so I'm looking to change them but not really sure what would work the best for a ratio.
 

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Depends on how big the tires are. 3.55s with 33" tires would be pretty sweet. That's what I would aim for.

You're really going to need a parts truck. It will be difficult without one.
 

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Discussion Starter · #5 ·
I really have no need for a parts truck being i have the axles which are off a 1987 Dodge W250 gas truck with manual locking hubs, a friend that is the biggest dodge truck guy I know and has four of every part you can think of including six 205 transfer case. So I'm getting the transfer casefrom him. I also have a brother that works in a machine shop where their building me a set of bullit prove drive shafts once i get a 5spd 4wd transmission and give them the measurements. I plan on running a set of 31-33" BFG ATs. Im just not sure the gear ratio. So you think 3.55 would work or should i go with something different?
 

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The cross member is different and the steering boxes are different also.

I think 3.55s would be nice even with 31" tires. Unless you happen to have a set of 3.73s. Use a RPM calculator and run some numbers and try to gear it where you want to be
 

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I think it wouldnt be that hard to do if you have the fab skills. Ive done a ford amd its a lot harder than the dodge looks. If i were you i would just run a divorced case or change out your mainshaft and get the tail housing to mate the tcase. It sounds like you have the right axles. I wouldnt hesitate to run a 3.54-4.10. I ran my 4.10's with 31's and its not all that bad just dont hurry. And my gmc has the 3.73's with 33's and its nice for hauling and cruising, best of both worlds. 3.54's and 33's would be good if you were more highway driving.
If i were you id leave the axles alone til you get it together and drive it. Then go from there.

As far as the steering box nothing is different just the pitman arm and maybe the steering shaft. Id build the axle hangers and shackles and mount them then do the steering and shocks then worry about the transfercase/transmission. Just my $0.02
 
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The 4wd box bolts to a plate that bolts to the frame. The plates are readily available at most dismantle yards. The bolt holes should already be in the frame to bolt it up. The plate has 4 holes that are for the box and 3 holes 1 with a stud installed in a tri-angular formation that bolts to the frame.
 

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I did the conversion a month ago so it's all still fresh on my mind but for the most part all the holes for the 4wd are there, but they will need to be drilled out but the rear shackle holes on the front were already in my frame and also if u want good heavy duty NEW front shackles I bought 2 inch drop shackles for 499 plus shipping off ramchargercentral just look up the guy Jungle he's the vendor

but back to the subject the hardest parts I came across was the 2wd sub frame removal I didn't drop everything out I just cut and made it work and look nice I have many pictures if u would like to see and another obstacle was the gearbox, u will need the 4x4 gear box and the mounting plate it moves it forward a few inches but the holes are there just need to be drilled bigger and my last problem was the brake lines, on the 2wd it has a 3 way valve on the frame on top 1 for rear and 1 for each front tire and the 4x4 has a 2 way for one to the front and one to rear


also note I had a donor truck on my hands I bought so I had references and all the measurements I needed
 
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Yes Cows has a very good write up.

Note though, his steering box mounting problems were due to starting with a 70's frame. Those trucks had a much different steering box mounting than the 80's trucks.

After 1980 or so, the holes for the 4wd mount are already there.

Most holes for the swap are present on 2wd frames. Only ones that I typically don't see are the holes for the shackles. There's measurements online for correct placement.

Couple gotchas here: the steering box moves a couple inches forward when swapped, you will need the correct steering shaft (Borgeson)
The trans crossmember is different for 6" vs 7" frame rails. The 7" crossmember has an extra channel to move the mounting pad up an inch.

To run the 2wd crossmember unmodified I think you need a 8" lift.
 
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