700R4 - essential to buy a newer case?

[JeepSJ]

Thanks Robyn, you need to make a sticky of that info!

My question is this.. I can't find an 89 K case. How terrible is it to use my 83 again? Is the difference significant?

The K case is heavier. They are easy to identify as there is a big K cast into the bellhousing. The difference is significant. It should not be hard to find one - just about any late-80's Chevy/GM truck with a big block or diesel should have one. I have seen lots of them in wrecking yards. When I bought my trans, I was able to order it with the K case.

[Robyn]

Yes you definately want a K case for your build.
The early trannies have several issues that you dont want to deal with.
I got a complete off ebay for my project.
While you are looking you can be gathering the other goodies.
Fresh converter
13 Vane front pump
Bushings and thrust washers
Gasket and seal kit
Transgo 2-3 shift kit
HD input drum
HD sun shell
2-4 band
Corvette 2-4 servo assembly
HD sprague
HD roller clutch
HD 3-4 clutch pack ( many outfits sell a package)
All the rest of the clutches can be of stock configuration.
Now be sure you get a V8 or diesel Tranny and not a V6 one.
The clutch packs and such are different.
I suggest doing it peace meal because otherwise you will have extra parts left over.
The tranny supply houses can do it this way for you.
Or you can buy a long overhaul kit with everything in one box and then add the special HD parts.
Once you get your goodies and before you do anything read the manual that comes with the Transgo kit.
Dont let a salesman sell you the small SK kit You want the 2-3 KIT (Big Box)
read that material untill you have it in your mind, untill you have the pages worn dog eared. The read it some more. The steps in the installation of the kit are critical and must be followed carefully.
When you have the box built then do the valve body on a clean clutter free bench. Dont use "red rags" around the tranny, use paper shop towels.
There are holes to drill, springs to change and all sorts of recomendations for the ON THE BENCH fix as opposed to in the rig.
These guys got it together and when its done the 700 will delight you every time it kicks you in the butt with a nice crisp shift.
DONT USE THE HYDRAULIC ONLY LOCKUP FEATURE.
Retain your electric lockup control.
Depending on what tranny you end up with youmay need to change the lockup solenoid to match your needs.
Or you can place control on a switch and let the tranny do the lockup with the valve body and shut the thing off around town via the switch.
If you find that your valve body does not have a lockup valve set in it we will cover that if and when it happens. ( some 700R4 boxes in the late 89 early 90 had electrical lockup only via the computer)
88-89 boxes were mostly valve shifted converter clutch)

OH if you find a 2WD model thats ok just change the ouput shaft to 4WD one.
You may get a better deal too. Also depending on what you get you MUST match the governor to the diesel. A gasser governor will shift it real goofy.
Get a diesel governor if you need one from the Chevy store.

Keep us posted

Robyn