TH400/NP205 swap to 208?

[454_72_4X4]

I'm just wondering what all it would take to swap out the 205 in my wife's 1980 K20 to a 208.
The 205 is the "figure 8" type bolt pattern.
Will the 208 and it's adapter just bolt on to the existing th400?
Also, would there be any driveshaft modifications needed? (The 205 that's in it now is the rear slip yoke not the fixed yoke/slip joint driveshaft.)

I know it sounds like a strange swap, (205 to 208...why would ya do that???), but I'm going to swap the 205 out of her truck into my 72 behind a NV4500 so I have to put something back into her truck.

[b454rat]

If you have the adaptor off the 400/208, then it will bolt on. Not sure on the d-shafts. You might have to get the shaft shortened, I think the 208s are longer than the slip 205s.

[454_72_4X4]

Originally Posted by b454rat

If you have the adaptor off the 400/208, then it will bolt on. Not sure on the d-shafts. You might have to get the shaft shortened, I think the 208s are longer than the slip 205s.

So far good news. (It will bolt on)
Right now I don't have the 208 or the adapter.
Getting the driveshaft shortened is easy enough.
Another question as long as we're on the driveshaft subject. Would the 205 slip yoke fit the 208? I think the 208's are slip yoke also, right?
Thanks for the info.

[4bynut]

As far as i've read you'll need a different tranny or at least the tail shaft. The info i got off another post showed these three tailshaft lengths for the TH400.
with 203 case - 1 3/8
with 205 case - 4 1/2
with 208,241 case - 2 1/2

Jason

[shilo]

I had a 400/208 combo and was looking into swapping in a 205. My tranny builder told me to find a slip yoke 205 off another 400 and it would bolt right in. same drive shafts and all. So if that works, im not sure if it does, i dont see why you couldnt do it the other way.

[1969 GMC]

Originally Posted by 4bynut

As far as i've read you'll need a different tranny or at least the tail shaft. The info i got off another post showed these three tailshaft lengths for the TH400.
with 203 case - 1 3/8
with 205 case - 4 1/2
with 208,241 case - 2 1/2

Jason

If thats the case (lame pun) couldn't you just cut off 2" of the tailshaft? Everything else should work, then.

[454_72_4X4]

Originally Posted by 1969 GMC

If thats the case (lame pun) couldn't you just cut off 2" of the tailshaft? Everything else should work, then.

Sounds good to me.

[454_72_4X4]

Originally Posted by 4bynut

As far as i've read you'll need a different tranny or at least the tail shaft. The info i got off another post showed these three tailshaft lengths for the TH400.
with 203 case - 1 3/8
with 205 case - 4 1/2
with 208,241 case - 2 1/2

Jason

Wouldn't happen to have a link to that thread would ya?

[4bynut]

Sorry i don't. I just wrote it down for reference when i read it. It was either on here or colorado K5. I have a complete TH400 - 208 combo still in a 1987 chevy long bed pickup. I'd consider selling the whole setup with crossmember, driveshafts, and all. If your interested let me know. Thank's Jason

[454_72_4X4]

Originally Posted by 4bynut

Sorry i don't. I just wrote it down for reference when i read it. It was either on here or colorado K5. I have a complete TH400 - 208 combo still in a 1987 chevy long bed pickup. I'd consider selling the whole setup with crossmember, driveshafts, and all. If your interested let me know. Thank's Jason

Oh well, thanks for the input anyway. I'll look around and see what I can find. The search doesn't work yet I don't think.
Don't really wanna buy another whole setup but if ya get really, really bored with nothing else to do, could ya snap a few pics of your 400/208 and adapter setup? LOL
Where's Sterling, IL? I'm just outside of Kahoka, MO. Maybe I could drive up and do some comparing sometime if it's not to far.

[4bynut]

I'm about 4hrs NE of you. I'll get you a couple pics. And i'll sell just the transfer case. Id like to keep the tranny anyway. What all would you be interested in. Thank's Jason

[454_72_4X4]

Originally Posted by 4bynut

I'm about 4hrs NE of you. I'll get you a couple pics. And i'll sell just the transfer case. Id like to keep the tranny anyway. What all would you be interested in. Thank's Jason

Pics would be great! I might be interested in the tranfer case as well. I guess it'd be the 208, shifter, and the adapter? Maybe the rear driveshaft if it's longer than mine. (If it's shorter I can have mine shortened).

LMK some $ figures and we might work something out.

[4bynut]

Here's a couple pics of the 208 and shifter i have. It's still in the truck so pics are not the best. I'll PM you later. Thank's Jason

[454_72_4X4]

Originally Posted by 4bynut

Here's a couple pics of the 208 and shifter i have. It's still in the truck so pics are not the best. I'll PM you later. Thank's Jason

That looks like it should work. The extension housing on the 205 in it now looks alot like your 208.
Shoot me a pm with some prices and if your not in a big hurry to get rid of it we might work something out.