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dreaming.....how to go auto in a truggy

pennsylvaniaboy

make fullsizes great again
Joined
Jun 27, 2020
Member Number
2192
Messages
929
So after wheeling a buddies rig that has an auto it has me contemplating if it feasible or affordable to do so. I currently have a 79 k30 truggy, its got a vortec 5.7, sm465/205/divorced 205. I dig the fuel injection, dont hate the clutch, and like the 4.1. But is there a way to go auto and which? I know the status quo used to be th400/203/205 but those are getting so hard to find after cash for clunkers. Could you put a 4l603 or 4l80e behind the motor again? The harness and computer were stripped and programmed by jims performance when i put the motor in.

If you went 4l80e what's the best transfer case solution? Currently I have 10 spline 205s and a divorced 205, obvisouly neither of these really mate to the 4l80e or th400 for that matter. Till you price a magnum box, or doubler is one better off going 3.1 or 4.1 atlas?
 
You can 203/205 a 4l80 as well. But depending on wheel base a 4spd would be shorter and deeper.

I run a fmvb 4l80 in my crewcab. A winters/artcarr/cheata shifter and you're golden.
 
What is the difficult part of a TH400 to NP203? The input gear of the NP203 is ~$150 new last I priced. I see the adapters pop up all the time in the $200 range or less. The output shaft of the TH400? Should also be in the $150 new range... I haven't looked or seen a price.:confused:

FWIW, my 'truggy' build is 4l80e and NWF Blackbox... a shit ton more money than the above.
 
You can 203/205 a 4l80 as well. But depending on wheel base a 4spd would be shorter and deeper.

I run a fmvb 4l80 in my crewcab. A winters/artcarr/cheata shifter and you're golden.

so no trans controller? But you then have to shift it for each gear? Is there a way to make it "auto" but not computer as much as factory?
 
What is the difficult part of a TH400 to NP203? The input gear of the NP203 is ~$150 new last I priced. I see the adapters pop up all the time in the $200 range or less. The output shaft of the TH400? Should also be in the $150 new range... I haven't looked or seen a price.:confused:

FWIW, my 'truggy' build is 4l80e and NWF Blackbox... a shit ton more money than the above.

they jsut keep getting harder to find the parts.
 
they jsut keep getting harder to find the parts.
Please clarify what parts are getting harder to find? I've already pointed out that the input gear and output shaft are still being made. The 400 to 203 isn't that hard to find... a simple ebay search found this guy for $120:
https://www.ebay.com/itm/th400-trans...kAAOSwvY5fJe8V

I haven't looked for an NP203 core(ie not 32 spline input) but I'm sure I could fall over a truck bed full of them for free. Rebuild kits are available.

I also haven't looked for a TH400 core(ie who cares if 2wd/4wd), but I'm sure one could find one much cheaper than a 4l80.

I haven't looked at adapters from 203 to 205 but I've lost count of companies making those adapters.

*edit*
Here is $155 np203 input:
https://www.offroaddesign.com/32-spl...nput-gear.html

*edit2*
Here is $185 400 output from AA(not known to be the cheapest source):
https://www.advanceadapters.com/products/52-7002--gm-4wd-t400-output-shaft/
 
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Jesus you really are soft as puppy shit arent you.

You can buy stand alone trans controllers from transgo.

thanks dick 🖕 Iam asking because no, I'n not sure on what the best route is. I know that gold standard has always been 203/20 doublers. Im asking if upgrading my current setup, if there are better or more modern options, and if so what is the best way to accomplish that. That's all.


Also glad to see the pirate attitude lives strong😁
 
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