Swapping 400 turbo into k1500

[bambam78]

Has anyone done this swap? My 700r4 took a dump on me, the truck never sees the highway and is mainly used for towing, so I was kicking around the idea of a 400 swap, the truck is a reg cab, 350,700r4,241,14 bolt

What I've gathered so far is
A 400 turbo has 32 splines
A np241 transfer case can have 27-32
A 208 adapter can be used to bolt them together

Now my question is, what trucks we're equipped with a 32 spline np241, will I have to modify my driveshafts? Will I have to modify my cross members? If I did have to modify my driveshaft would the stock driveshaft out of a reg can long bed 3/4 fit, with matching u joint of course

Any info from Someone who has done the swap would be awesome

 

[volunteerff21]

3/4 ton trucks had the 32 spline NP241, the one ton trucks used a Borg Warner transfer case, although I believe those were also the same spline count.

I think the 27 spline and the 32 spline should be the same size case.

 

[98_k1500]

The cases are the same. All manual trans trucks and the 4l80 equipped trucks are 32 spline, the 700r4/4l60 trucks are 27 spline. The transfer input is the only difference. They will interchange, but i have never done one and have no idea how much is involved in removing the transfer input shaft. The borg warner is 32 spline.

 

[Kurnacopia]

I have done the exact reverse of what you have here. I have a 78 Scottsdale 4x4 that had a 350/350/np203. I went with a 700r4/np241 out of an 89 v1500 suburban. I had to modify the placement of the tranny mount a few inches, then replace the old front drive shaft with a longer shaft (same one from the suburban) and now I have to replace the rear shaft. I did do a SYE kit which eliminated the crappy slip yoke that's prone to leaking on the np241. That was a really cool job and it wasn't hard to do. Note?: The 700r4 came with the np241 adaptor and its a 27 spline unit....even after the SYE swap. Lastly, you may need an different transmission mount. Mine came from an 89 suburban and I adapted it to my frame as needed.

 

[NickTransmissions]

I have done the exact reverse of what you have here. I have a 78 Scottsdale 4x4 that had a 350/350/np203. I went with a 700r4/np241 out of an 89 v1500 suburban. I had to modify the placement of the tranny mount a few inches, then replace the old front drive shaft with a longer shaft (same one from the suburban) and now I have to replace the rear shaft. I did do a SYE kit which eliminated the crappy slip yoke that's prone to leaking on the np241. That was a really cool job and it wasn't hard to do. Note?: The 700r4 came with the np241 adaptor and its a 27 spline unit....even after the SYE swap. Lastly, you may need an different transmission mount. Mine came from an 89 suburban and I adapted it to my frame as needed.

That post was from 10 years ago and member 98_k1500 hasnt been seen since 2018...That said, the above project looks great - perhaps consider starting a build thread showing all the progress, etc...

 

[Kurnacopia]

That post was from 10 years ago and member 98_k1500 hasnt been seen since 2018...That said, the above project looks great - perhaps consider starting a build thread showing all the progress, etc...

I never expected to still see a post that was that old. I dont wish to start a new build page.....I mean I could, but the negativity gets overwhelming. Thanks for letting me know.