Manual to auto swap

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kychevy

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My daughter has just informed me she wants her truck to be an automatic now.(‍♂️Dang women and changing their minds) The truck has been an auto b4 and PO switched it to manual. Truck has 3.08 gears, supposedly a stock 94’ 350, and 35” tires. Don’t know which of the autos I should put in it…..350, 400, or the 700r4. Oh, Transfer case is the 205 but might change to the 208, all according to cost, though. This is her 1st vehicle so not looking to spend a fortune on it. The cab was an 87 2wd and still had the auto steering column but not sure if anything else. Any input appreciated.
 

SquareRoot

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A gas guzzling classic squarebody for a first vehicle whan fuel is $4/gallon. Sweet! Tell her a manual transmission is a bulletproof ant-theft device. Even better, convince her she wants an NV4500, smaller tires and keep the 205. Then everything in the universe will be right.
 

nvrenuf

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Odds are that the tcase has a 10 spline input whereas automatic transmissions will be 27 (th350, th700) or 32 (th400). At the very least you’ll have to swap the tcase input shaft.
 

Curt

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I personally think a manual makes a better driver.Driver input keeps you more engaged.

The SM465 is just about bullet proof if the 2nd gear issue has been updated.The 205 is just about bullet proof as well.The 208 is a good case,but is fragile compared to rocks.

If you’re one in a million,you have a round pattern 205/465 and it is 32 spline.Very strong.

If anything,if she decides later she wants something else,you have a nice hunting wagon/toy.

My last trade in was a manual and the dealer said it would sit because very few people want one….I personally think it’s because No knows how to drive em anymore.But,newer trucks are a far cry away from the dump truck style 465 shifting.
 

RecklessWOT

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Personally I would prefer a standard in a pickup that isn't heavily used for towing, but my opinion doesn't matter in this instance, it's up to your daughter :waytogo:

If she really is dead set on an auto, with your setup I would say go with the 400. Similar but decently stronger than the 350. That setup is all wrond for the 700r4, most of the time yes having OD is nice for fuel economy, but with 35s and a 3.08 rear the 700r4 would not be happy, the 1-2 shift is drastic, and the OD is silly tall on those transmissions. It would move around good in first, fall off a cliff and struggle to accelerate in 2nd, and it would rarely shift into OD unless you were going quite fast on the interstate and would jump back to 3rd if you so much as think about a hill, and then I can almost guarantee it would basically never lock the converter.

My 'burb has a 700r4 and had 3.73s, on 31s it was pretty much fine, when I switched to 33s it became a struggle to drive. I wouldn't want to imagine 35s with 3.08s, you'd probably burn the trans up.

TL;DR- if you're going auto I'd say get the TH400. But keep in mind what others have said about compatibility with the t-case
 

Catbox

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Yup.
You should think of having to regear the pumpkins as well.
It will make things happier in the long run with numerically higher gears in there.
The engine will have to work less, thus saving some fuel...
 

RecklessWOT

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Yup.
You should think of having to regear the pumpkins as well.
It will make things happier in the long run with numerically higher gears in there.
The engine will have to work less, thus saving some fuel...
Well, 35s and 3.08s would actually probably be okay with a 3spd. Definitely too tall for an OD trans, but a 350 or 400 honestly that should be right in ste sweet spot if you do highway driving. If it's strictly a low speed around town rig then yes I would go shorter than 3.08. What kind of RPMs you running with the manual?
 

kychevy

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Yup.
You should think of having to regear the pumpkins as well.
It will make things happier in the long run with numerically higher gears in there.
The engine will have to work less, thus saving some fuel...
I am really considering that as an option. Thinking of 3.55 or 3.73’s. I am still trying to persuade her to go with the manual but she is a little intimidated by it. Kindof hard to get taken off with those tires and gear combo.
 

kychevy

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Well, 35s and 3.08s would actually probably be okay with a 3spd. Definitely too tall for an OD trans, but a 350 or 400 honestly that should be right in ste sweet spot if you do highway driving. If it's strictly a low speed around town rig then yes I would go shorter than 3.08. What kind of RPMs you running with the manual?
It’s been in my shop for past month but I believe around 1800-1900 @ 70ish. She’s a farm girl so it would be mainly for around town and on the farm.
 

Ricko1966

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Should have read better before I started posting,sorry. My reply was relevant to 2wd,not 4wd.Carry on.
 
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whiskeydents

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Where are you located? I have a turbo 350 with the np203 still attached from my manual swap. And I have all the fixings
 

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