Author Topic: Tall and short TH400 to NP208 adapter- 1981 Chev Scottsdale K10  (Read 295 times)

Offline lyndoncp

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Tall and short TH400 to NP208 adapter- 1981 Chev Scottsdale K10
« on: November 26, 2018, 01:44:12 PM »
I am in the middle of putting a BBC in my truck and thought I had better upgrade from the TH350 transmission to a built TH400. I have the transmission built and the input shaft changed in my 208 but now I need to mate them up.
I have a flat crossmember and the tall adapter between my Th350 and the 208 right now. I am having a heck of a time trying to track down a tall adapter for the TH400.

Two part question, would it be easier to just change crossmember than to find the tall adapter? Any ideas who makes an aftermarket adapter?

Offline fitz

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Re: Tall and short TH400 to NP208 adapter- 1981 Chev Scottsdale K10
« Reply #1 on: November 26, 2018, 05:58:21 PM »
  Most Military CUCV's ran turbo 400/208's with a flat crossmember & a tall adapter.
These truck is are basically mid 80's chevys with a few Military options.
  Check on craigslist. Lots of guys part these trucks out to get their hands on the front Dana 60 & 14 bolt rear with 4.56 gears with a Detroit locker.
  Where are you located?
  Google Hilbilly Wizard.  He runs a business parting out Military trucks.  I just checked, he is selling the adapters for $210. 

Offline lyndoncp

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Re: Tall and short TH400 to NP208 adapter- 1981 Chev Scottsdale K10
« Reply #2 on: November 26, 2018, 07:12:41 PM »
Hey thank you very much for that info, very much appreciated. I actually tried to buy that one off his site but he doesn't ship all the way up to Canada.

I'm actually really close to the border and now that I think of it I know a guy just on the Montana side of the border with a bunch of the military square bodies I may try hitting him up.

I see there is a few on Ebay too but man I'll be into one of those about $350 CAD by the time it ends up at my door.

Offline lyndoncp

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Re: Tall and short TH400 to NP208 adapter- 1981 Chev Scottsdale K10
« Reply #3 on: November 26, 2018, 07:14:57 PM »
What do you think about fabbing up a spacer for between the current crossmember and a short adapter??

Offline Irish_Alley

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Re: Tall and short TH400 to NP208 adapter- 1981 Chev Scottsdale K10
« Reply #4 on: December 05, 2018, 05:27:13 PM »
wont be too bad if its secured right or even making a new crossmember
If you canít tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Offline fitz

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Re: Tall and short TH400 to NP208 adapter- 1981 Chev Scottsdale K10
« Reply #5 on: December 05, 2018, 09:07:00 PM »
Try putting an ad on Craigslist to buy 1.
I sold a turbo 400 bolted to a 208 complete with the flat crossmembet for $250
It was from a running & driving CUCV.
They are out there.

Offline lyndoncp

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Re: Tall and short TH400 to NP208 adapter- 1981 Chev Scottsdale K10
« Reply #6 on: December 23, 2018, 09:26:29 PM »
Well here was my solution. Difference in height was exactly 4 inches so I glued a couple 2x2 square tubes together and drilled some holes. Wish me luck!

Offline JohnnyPopper

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Re: Tall and short TH400 to NP208 adapter- 1981 Chev Scottsdale K10
« Reply #7 on: December 25, 2018, 04:57:23 PM »
Very Clever!

I would glue the nuts in place and then cap the ends.

What gauge is the 2x2? 

Offline lyndoncp

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Re: Tall and short TH400 to NP208 adapter- 1981 Chev Scottsdale K10
« Reply #8 on: December 25, 2018, 09:12:34 PM »
2x2 is 3/16

I like the idea of spotting the nuts in place.. hmmm
when you say cap the ends what do you mean??

Offline Irish_Alley

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Re: Tall and short TH400 to NP208 adapter- 1981 Chev Scottsdale K10
« Reply #9 on: December 26, 2018, 07:09:00 AM »
think he means capping the ends of the box tubing so no mud and crap gets in
If you canít tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Offline JohnnyPopper

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Re: Tall and short TH400 to NP208 adapter- 1981 Chev Scottsdale K10
« Reply #10 on: January 02, 2019, 12:54:19 PM »
Irish nailed it, close the ends to stay clean and add rigidity.