tranny question

[tek970chevy]

i have a 700 in my 70 and it just went out... thinking of getting a 400and was wondering if i had to change/modify anything to put it in... from what i know, the driveshaft as been shortened to fit the 700 from when my dad had it... dont know if i have to do anything else... please help.. thanks

[tek970chevy]

Forgot to ask if anybody knows... when it comes to the torque converter. What exactly is the STALL?
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[So.Cal.Super]

here is a link for the reverse swapping 400 to 700r4

http://67-72chevytrucks.com/vboard/s...ad.php?t=33266

You do realize that your going from an Overdrive tranny to a 3spd?

And for your second question are you asking what the stall speed should be or ?

here is an article I liked regarding converters

http://www.carcraft.com/techarticles...ter/index.html

Hope that helps, I'm sure someone who has done it will chime in.

[tek970chevy]

So is overdrive considered better? Its my understanding that it helps mpg but what I really want something strong that'll pull
And yes I wanted to know what the stall speed should be
And if I do get the 400 will I be able to use the same dipstick and cable from the 700?
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[tek970chevy]

So is overdrive considered better? Its my understanding that it helps mpg but what I really want something strong that'll pull
And yes I wanted to know what the stall speed should be
And if I do get the 400 will I be able to use the same dipstick and cable from the 700?
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[custom1970]

unless your trying to go with and original set-up, i think you'll be better with the 700, better fuel economy, better for your engine (lower highway RPM), among other things. And i definitely would not use a dip stick from a different type of trans

[Longhorn Man]

it depends on how your truck is set up, and what you'll be using it for.
You mentioned pulling... it you tow a lot, then go for the 400
Even just dropping a 700 in 3rd for towing, it's still not all that strong.
If your truck is a 1/2 ton, there's a good chance that you have a 3.07 gear and that is a good freeway gear to begin with. If you had an overdrive and the 3.08 gear, your MPG may actually go up with the 400 trans.

The 400 does not use a kickdown cable at all. You will want to hook up a kickdown switch. You don't NEED it, but it makes things easier, and it will extend the life of the trans a bit.
You will want a dipstick and tube from a TH400.
As far as your stall speed, it again depends on intended use, gearing, and how your engine is built. However, if it is a stock engine, then just get a converter for a stock truck.

[cdowns]

you cant use the 700 dipstick for the 400/you cant use the driveshaft you have/ there is no cable with the 400 it has electric switch that you need to hookup

[So.Cal.Super]

When it comes to Stall I will point out a paragraph from the link I posted.

After you’ve declared your intent for the car, you also need to tell the tech guy the weight of your vehicle, and the following information about your powertrain combo:

• Displacement

• Compression ratio

• Cam profile (duration at 0.050-inch lift, lobe separation angle)

• Carburetor or injector size

• Transmission model year and gear ratios

• Rearend gear ratio

So my next questions are

what do you plan on Hauling?

What motor is in the truck?

Is it stock? will it stay stock? if your going to build it, how long after the new trans goes into place?

What rear end is in the truck?

I've seen plenty of SBC Run great with th350's and 700r4

The 400 is a monster and with a stock 350 IMO would be a dog with a 400

Then there is the 4L60 Option also

I have a 402 with small build up maybe 320hp th400 and 4:10 rear that I avg 7.5 mpg with but I also drive it at 70mph and I hate that it's almost turning 3000rpm. Not good for the life of the engine.

Your going to want to use the correct dipstick like custom said. the cable i'm not sure on.

[So.Cal.Super]

I took too long to type

[tek970chevy]

Originally Posted by Longhorn Man

it depends on how your truck is set up, and what you'll be using it for.
You mentioned pulling... it you tow a lot, then go for the 400
Even just dropping a 700 in 3rd for towing, it's still not all that strong.
If your truck is a 1/2 ton, there's a good chance that you have a 3.07 gear and that is a good freeway gear to begin with. If you had an overdrive and the 3.08 gear, your MPG may actually go up with the 400 trans.

The 400 does not use a kickdown cable at all. You will want to hook up a kickdown switch. You don't NEED it, but it makes things easier, and it will extend the life of the trans a bit.
You will want a dipstick and tube from a TH400.
As far as your stall speed, it again depends on intended use, gearing, and how your engine is built. However, if it is a stock engine, then just get a converter for a stock truck.

so if it doesnt have a cable the only thing it really has is the shift linkage to the steering column?... and if i get the the switch where would it have to be hooked up on and how?

[tek970chevy]

Originally Posted by cdowns

you cant use the 700 dipstick for the 400/you cant use the driveshaft you have/ there is no cable with the 400 it has electric switch that you need to hookup

i cant use the driveshaft i have??? never heard that before.. why??

[cdowns]

Originally Posted by tek970chevy

i cant use the driveshaft i have??? never heard that before.. why??

because it wont work because they are different types

[tek970chevy]

Originally Posted by cdowns

because it wont work because they are different types

? what do you mean??

[So.Cal.Super]

Different Transmissions are different lengths. When you go from a 400 to a 700r4 you have to have the drive shaft shortened. So in your case you will need a longer driveshaft to go from the 700 to the 400

[Longhorn Man]

Shift linkage and a vac line, and then the kickdown switch, which you'll be best off getting an aftermarket deal like maybe lokar. Stock was a button mounted on the intake that the arm on the carb linkage would press at wide open throttle. You'll want positive to the switch, then the other wire off the switch goes to the terminal on the side of the tranny. It's been a couple years since I looked at one so I can't say where it is on the tranny, other than on the side of the case and kinda low.
The drive shaft issue... most shops won't make a drive shaft longer. They'll chop the ends off your shaft and make a new tube though. It'll be cheaper to locate one off a TH400 truck with the same type engine you have (small block/big block/inline6), but that could be hard to locate. The yoke may need replacing too, not sure.

[tek970chevy]

thanks guys that helped alot... talked to my dad, and he advised me to get the original 350... last time i didnt take his advice i ended up spending way much more...but i still kinda want the 400 lol

[Wrenchbender Ret]

The 400 uses a larger yoke then the others.