700 r4 in a K20?

[leddzepp]

I have a chance to pick up a 700r4 transmission for free, it is a non computer controlled unit. I’m not sure what it came out of originally but am wondering if I can use it in my 72 K20? Do I need a special 4x4 adapter to connect it to my np205 transfer case, or can I use the one from my th350 that’s already there? Thanks in advance.

[57taskforce]

There’s a few ways to skin this cat. The first is a shortened transmission output shaft that will then let you use the th350 adaptor to your 205. The second is a spacer that goes between the adaptor and the transmission that lets you keep the stock Kcase 700r4 output shaft. If your going to go thru the tranny use option 1. I looked into this a year or two back so this is just the gist of it. If I remember right you may have to move the motor forward because the 700r4 is longer than the th350. Don’t quote me on it though.

I was in your neck of the woods last month in my Camaro. The freeway can be pretty fun with 400hp and a 6 speed. If I was in my K20 with no overdrive, not so much. It’s not that I worry about the engine speed or anything like that, I just don’t care to go 80-90 in that beast.

[special-K]

Yes, you move engine forward so the transfer case stays in the same place so the driveshafts can go untouched.

[jocko]

If trans is a 2WD unit, need the shortened output shaft HERE

Original K-case is slightly stronger because of a 6-bolt torque converter cover, but unless you're going baja, probably not necessary.

Torque converter cover bolt holes may be a clue - I think if 2WD, there may only be 4(?) K-case had 6 I believe.

EDIT: I believe doing the output shaft swap and moving the engine fwd as Tim mentions is the preferred approach.

[leddzepp]

Sorry, I should have specified the 700 is a 2wd transmission. Thanks for the input so far everyone!

[Mts67C10K20]

Did this last year
All correct so far
You need an output shaft installed for a 4x4
You can use a stock one with advanced adapters , adapter
Or a modified shaft and a 350t adapter
Then move motor forward 2"
Also will need the presure cable and carb bracket and a lockup kit
There are many out there
Have fun
Having overdrive is the only way to go imo

[Bigdav160]

I've done it too and used the AA output shaft.

Things I learned:
my factory 4x4 fan shroud no longer fit
the coolant hoses had to be modified
my A/C lines had to be modified
I had to move the shift linkage forward on the frame
I notched the front crossmember for crank pulley clearance
The transmission pan is really close to the front driveshaft but clears possibly because I have a 2" lift
The exhaust pipes had to be lengthened

Otherwise I would do it again