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Changing slugs to manual locks

Gtlackey

Gtlackey

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We are working on my sons new to us 74 Jimmy and looking or convert to an NP205 for 4 to 2. he currently has slugs on it due to the fulltime. How much do we have to change up front in the axles and differential to move to manual locking hubs from the slugs?
Seems it’s more the just a set of $115 manual locks…
Somewhere I saw $2k kit. For that much I can get a whole new rear end?

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You can just swap the hubs. The driveshaft will still spin, NP203 full time mode. It will have better road manners and slightly better mileage. Drove one that way for years.
 
But we are going or put in a NP205 as well, my goal is a true 4 to 2. So if I out in the MM hubs I will be there?
 
Yes. The NP205 is a normal 2hi - 4hi - N - 4 lo transfer case. The NP203 has the center diff setup to allow it to run as a full time case. The t case swap is the hard part. Correct adapter, new drive lines, crossmember mods, etc.
 
Yes, I am familiar with all those changes but I feel it will be worth it in our situation. Crossmember move is the biggest, already changing driveshafts, so will just adjust length…
Thank you for the reply and info! I will keep y’all updated
 
Is the transmission a stock 350 or 465, only asking because if someone swapped in a T400 at some point (a lot can happen in 48 years) you’ll need a different output shaft as the 203 one will not work.
 
no, it is still original TH350 and 203 case. I am putting in a new TH350 with a NP205 to convert that connection point and then locking hubs to convert that side so I can go to true 2wd
 
It's just taking the hubs apart and putting in the lockable ones.

I bought MM manual hubs, still haven't got around to putting them on.

I've been driving my '74 with a sm465/np205 swap for 2 years now. There has been no issues with the slugs still on it. The front driveshaft spins but there is no power to wheels.
 
I just put up a new post about swapping to a 700r4 in the process. If I already need to change drive shafts, move shifter and move crossmember for the NP205, why wouldn't I just go ahead with the 700r4 swap if I can get my hands on a good one at a reasonable price instead of rebuilding my TH350? can check the other post or add here if you have advice.
thanks all!
 
I personally wouldn’t go to the trouble of swapping in a 700R4 in place of a 350, if you’re going to swap something different in swap in something worthwhile like a 4L80
 
Chickntrk said:
I personally wouldn’t go to the trouble of swapping in a 700R4 in place of a 350, if you’re going to swap something different in swap in something worthwhile like a 4L80
Click to expand...
I was trying to stay away from the electronics there and keep it simpler, is that a mistake?
 
My experience is that the 700R4 is not a very robust transmission. There are stand alone controllers for the 4L80 as well as an option to go to full manual control, your mileage may vary but personally I’d rather have a T350 than a 700R.
 
the shifter won't move for th350 from np203 to np205. It will be in the same place.

The 1 reason to consider the 700 over the 4l80 is 1st gear on the 700 is 3.00. Overdrive is .70 on the 700r4 and .75 on the 4l80. The 4l80 is a great trans but the initial dollars to get there is more, but way stronger. I'm on my second 700r4, thou I am thinking I messed up the first one. #2 has 20k miles and going strong.
Before I did the th350 to 700r4 swap i had only done the np205 swap, I used the rear drive shaft I had from np205 sm465 truck. Truck was full on usable daily'd 4.10 with 33's for years.
 
So in summary, 700r4 a good bang for the buck for an OD and not too hard to swap. since I am already swapping the 205 in anyway?
In addition, if you rebuild it with hardened insides does well without getting into electronics.
I just don't want to go to all the effort of adjusting everything just for the 205 and then regretting not going all the way...
thanks for all the input everyone, especially Wes!
 
Thanks everyone, it looks like after all the ins and outs, we are probably going to stick with the TH350 and rebuild it and the NP205 transfer case we have.

Had long conversation with a drag racing friend whose father owns Trans shop, he said for our application of a lot of around town driving with some longer distance highway towing; he recommended against the 700r4 convincingly. Basically if TH350 ad differentails geared right, the extra gas mileage was not worth the extra potential issues with the overdrive towing on highway...
will also save Jonathan some $$ for now and teach him a ton...
 
If I had to do it all over again, I'd keep my th350, and put 35s with 4.1 on my truck. Lol it's getting 35s next time, but now 4.88.

Dang it man now I want 6L80
 
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