Author Topic: Ls swap advice in an 81 k10? Please and thank you  (Read 5901 times)

Offline billyt33

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Ls swap advice in an 81 k10? Please and thank you
« on: March 06, 2015, 12:44:34 AM »
I've got a 1981 K10 and it currently has a 305, NP205 transfer and I'm not sure the tranny.  I just bought a 5.3 with 110k out of a 2004 Silverado with the 4l60e, computer, harness, radiator, fuel pump, gas pedal and he even threw in the transfer and break booster.

I've got a few questions:

- Is there a way around spending the $767 for the adaptor from advanced adaptors to connect the 4l60e to the NP205?

-What is the best way to go about mounting the 4l60e?

-I'm thinking dirty dingo motor mount adaptors.  Are they any good or would you recommend something else?

-any upgrades that would be worth while for the 5.3 before put it in? (either performance or cosmetic that won't break the bank)

-should I use the radiator out of the donor or would it be better to go after market?  Any suggestions or recommendations?

-am I going to have to get custom drive shafts or is there a way to make the stock ones work?


I think that's it for now.  Thanks I appreciate it.

Offline Irish_Alley

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Re: Ls swap advice in an 81 k10? Please and thank you
« Reply #1 on: March 06, 2015, 12:53:59 AM »
imo the 4l60e is a 27 spine t case. your 205 would have to be off a 700r4 or a th350 to fit then like said you need the adapter then a electric speed sensor. is the 4l60e 4x4 or 4x2? if its 4x2 i would think about selling your old setup and buying a divorced 205 and get some new driveshafts (have to get them no mater what)
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Offline Irish_Alley

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Re: Ls swap advice in an 81 k10? Please and thank you
« Reply #2 on: March 06, 2015, 12:54:25 AM »
oh yeah welcome from delaware
If you canít tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Offline billyt33

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Re: Ls swap advice in an 81 k10? Please and thank you
« Reply #3 on: March 06, 2015, 01:13:51 AM »
Thanks I appreciate it.  The 4l60e is a 4x4.  Where can I get an electric speed sensor and how do I install it?  Also I have the transfer case that came with the 4l60e. Is there anything I can do with that or is it more trouble than its worth?

Offline Irish_Alley

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Re: Ls swap advice in an 81 k10? Please and thank you
« Reply #4 on: March 06, 2015, 01:47:11 AM »
that t case on the 4l60e is a driver side drop, you make a ford front axle work but might be a pain. the 91 v3500 crew cab came with a 4l80e/205 and the 205 has a electric speed sensor.

idk if this is any good or not but its an ideal
http://forum.73-87chevytrucks.com/smforum/index.php?topic=30479.0
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Offline roundhouse

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Ls swap advice in an 81 k10? Please and thank you
« Reply #5 on: March 06, 2015, 06:18:53 AM »
The 87-91 blazers burbs and 1 tons had a passenger drop t case that should bolt up to your 4L60

Keep the transfer case that came with the 4L  for now.   You may need the input shaft from it to swap into the NP-241 t case from a blazer or burb






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« Last Edit: March 06, 2015, 06:23:58 AM by roundhouse »

Offline Irish_Alley

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Re: Ls swap advice in an 81 k10? Please and thank you
« Reply #6 on: March 06, 2015, 06:25:26 AM »
The 87-91 blazers burbs and 1 tons had a t case that should bolt up to your 4L60

Keep your 4L  for now.   You may need the input shaft from it to swap into the NP-241 t case that should work






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did think the 700r4 came in 1 tons? thought those were only th400. but they were also cable driven speed sensors
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Offline billyt33

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Re: Ls swap advice in an 81 k10? Please and thank you
« Reply #7 on: March 08, 2015, 02:08:56 PM »
Thanks from Maine.  I'm probably going to try and hunt down that 205 out of the 91 but from what I can see they seem to be pretty rare.  I called advanced adapters to see how the adapter would work with the vss and the guy was no help. He didn't seem to have any idea what I was talking about and was not very reassuring

Offline Irish_Alley

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Re: Ls swap advice in an 81 k10? Please and thank you
« Reply #8 on: March 08, 2015, 03:55:52 PM »
they are rare. took me almost a year but i have two of them. ones in a 91 v3500 and the other came from a southern states truck. dont think its a 91 but its a round 205 with 32 splines. i was going to make an adapter but then i found the 91 crew cab and it had everything i needed
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Offline roundhouse

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Re: Ls swap advice in an 81 k10? Please and thank you
« Reply #9 on: March 08, 2015, 10:35:09 PM »
A round 205 is rare

A 32 spline 208 is much easier to find and way cheaper

Or you could get a 88-91 blazer or burb NP241 and swap your input shaft from your 241 that is behind your 4L60 into it


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Offline 84Silverado4x4

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Re: Ls swap advice in an 81 k10? Please and thank you
« Reply #10 on: March 15, 2015, 09:54:53 AM »
I did my 06 5.3 with 4l60e in my 84 k10 and used advanced adapters to mate my np208 transfer case.  If you do something like this I would advise having a 700r4 shaft installed in the 4l60e to get your VSS signal with the reluctor ring.  I also used dirty dingo adjustable mounts and it worked out good but my engine was adjusted all the way back to clear the front crossmember and it comes very close to the firewall.  I also needed a lokar shift linkage to come off my column as the stock shift rod wouldn't work.   Also I used 2012 camaro exhaust manifolds and down pipes with cats and it worked out great!  It almost connected directly to my existing dual exhaust from my 350.  The stock trans crossmember will be set back just a touch and I just drilled new holes in the frame and bolted it right up.
« Last Edit: March 15, 2015, 09:59:15 AM by 84Silverado4x4 »

Offline Displaced_Txn

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Re: Ls swap advice in an 81 k10? Please and thank you
« Reply #11 on: March 23, 2015, 03:14:59 PM »
or you can get a np241c out of a 90-91 k5, surburan will still be floor shifted, have vss, and passenger side drop.




I also did see on another forum where they took the tail housing from thenp241 with vss and replaced the np208 housing with it.

Offline roundhouse

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Re: Ls swap advice in an 81 k10? Please and thank you
« Reply #12 on: July 29, 2015, 09:19:05 PM »
Those ports look to be in the same place as a stock square body rad?

Lot cheaper to get a local shop to move the ports
On a stock rad if you need em moved


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