LS 4x4 swap-need help planning!

[misternash2]

hey, i've found a 4x4 blazer that i'm very interested in. unfortunately, i don't have time to properly plan this project, and i won't have time to figure costs if i can't skip a stage. that's where you guys come in, i hope!

1985 blazer. 2004 5.3/4l60e 2 wheel drive is the engine and trans combo that i've got right now. it's swapped to a suburban, by me, so i'm familiar with the engine/transmission portion of it. my question lies in the transmission and transfer case. it has a np208 in it that's pretty freshly rebuilt. i'm wanting to keep the transfer case in the stock location so i don't have to cut 2 drive shafts. i've heard the np241 will bolt right up to the 4l60e. can anyone shed some light on the subject? as i said, i need to learn fast. i'm on a tight timetable and need to decide if i'm buying the blazer! thanks guys!

[misternash2]

just fyi, i've done the 5.3/4l60e swap twice, so i'm familiar with that aspect. i'm really needing help more with the 4x4 part of the equation now. thanks again!

[Jonboy]

NP241 is very similar to NP208, except it is set up for electric speedo. They were found in 90-91 V series trucks. That would be a direct swap, if you can get the 4WD 4L60E. Worst case, get the 4WD output shaft from the 700R4 in the Blazer now put in your 2WD 4L60. That would be a good time to freshen the trans so you know what you have.

[misternash2]

Okay, help talk me through this.

One option is find an np241 from a square 90-91 which would bolt right in. What would have to be done as far as driveshafts? Would I need new ones cut? And how about linkage? Would it be something easy to modify I'd assume?

The other is to have the output shaft changed in my 2wd transmission. Which has the cost of the transmission guy, plus having to run an adapter would mean 2 driveshafts as well since it would no longer be in the factory location.

If all that is correct, the obvious choice would be to source an np241 from a square. Assuming I won't need new driveshafts, of course.

I called my local salvage yards. One wanted $350 and one wanted $250 for the np241. But they were both for four speed autos aka 700r4. Id be looking for one for a 3 speed th350 as far as splines go, correct?
Posted via Mobile Device

[Jonboy]

I don't think the 241 case ever had a th350 in front of it. I am not sure of the spline count on the 208 case with a TH350, but a 241 is dimensionally identical to the 208 (as far as I know). The driveshafts, shifter linkage, and crossmember should be a direct swap. If it was me, get a 4wd 700/4L60 output shaft, put it in your existing 2wd 4L60E trans, and run a 241 case.

[misternash2]

Thanks man. I appreciate the help. The drive shaft thing was really what had me concerned. I think I'll be money ahead to buy the np241 and a low mileage 4x4 4l60e from the salvage yard and sell the 2 wheel one, the 700r4 from the blazer, and the np208. I'll go ahead and buy it and just hope that it doesn't end up costing too much. I really hate doing things that way, but sometimes that's how things go. The blazer is a good deal anyway...
Posted via Mobile Device

[83GMCK2500]

NP 241 would've came behind a 700R4, 4L80-E, or SM-465. The 700 version is 27 spline, the 80E is 32 spline, and I am not sure on the -465 version.

So, anyone that says "it came from behind an auto" needs to clarify WHICH AUTO.

[77dwh]

I just did a 5.3 4l60e 241 swap into my 77 chevy half ton 4x4. The 208 or 241 will bolt directly to the 4l60e. Keep in mind the 4l60e is an advanced version of the older 700r4. I used a 241 with the speed sensor built in to feed the pcm its speed signal and then used the 91 suburban cluster to get away from the speedo cable completely. Use either t case and it will bolt on to the 4l60 no problem.

[lowrodderchev]

Not to thread highjack but any certain year of 208? I'm currently doing a swap on my 75 and having a hard time finding a 241 passenger drop. I currently have a 4l60e 4x4 trans

[68Timber]

I'm wondering if the output shafts of the 208 and 241 are interchangeable and if so, is there any money saved going that route. I'm guessing the electronic signal on the 241 is coming from some type of reluctor ring?

[lowrodderchev]

I notice some guys just run a 205 what do they do about the speed sensor?

[83GMCK2500]

Some '90 (I think) and '91 (for sure) transfer cases in square bodies have the VSS. 1500/2500 will be NP241, 3500 will be NP205. Those behind a TH350/4L60(700R4) will be 27 spline input, from behind a TH400/SM465 will be 32 spline input.

[68Timber]

I'd call or email Novak Enterprises and see if the electronic speedo bits in the 241 can be put on the more common 208. http://www.novak-adapt.com/knowledge...cases/np241or/

[Grod67]

I am building a 1955 chev truck ,on a 1983 3/4 ton chassis. I have a 2006 3500 6 liter 4x4 . I'm thinking about installing in my 55, engine and trans. Will a np241 transfer case bolt up behind the trans? I need a passenger side drop.

[lowrodderchev]

Originally Posted by Grod67

I am building a 1955 chev truck ,on a 1983 3/4 ton chassis. I have a 2006 3500 6 liter 4x4 . I'm thinking about installing in my 55, engine and trans. Will a np241 transfer case bolt up behind the trans? I need a passenger side drop.

what size is the tranny? I'm running a 4L60E bolted right up to my NP241. I heard that Np208 bolts up to but they don't have the VSS