The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1973 - 1987 Chevrolet & GMC Squarebody Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 12-18-2012, 04:32 AM   #1
shipma2
Registered User
 
Join Date: Aug 2011
Location: manti utah
Posts: 95
th350 to th400

how much is a shop gonna charge me to have a th400 put in my 78 k10? its to low for me to do sense I dont have a lift what all will need to be done
shipma2 is offline   Reply With Quote
Old 12-18-2012, 05:49 AM   #2
bk2life
Account Suspended
 
Join Date: Oct 2012
Location: phx, az
Posts: 868
Re: th350 to th400

Quote:
Originally Posted by shipma2 View Post
its to low for me to do sense I dont have a lift what all will need to be done
pull the motor with trans, swap trans, put assembly back in if that is an option?

question, why 350 to 400 anyways?

price id say no less then 600 for a shop to do it.
bk2life is offline   Reply With Quote
Old 12-18-2012, 06:20 AM   #3
shipma2
Registered User
 
Join Date: Aug 2011
Location: manti utah
Posts: 95
Re: th350 to th400

cause it has a 454 in it the th350 crash shifts and broke a tooth off my ring gear in my rear diff
shipma2 is offline   Reply With Quote
Old 12-18-2012, 06:32 AM   #4
donut
Registered User
 
donut's Avatar
 
Join Date: Aug 2009
Location: S.C.
Posts: 1,593
Re: th350 to th400

Not going to quote a price, but looking at the same swap for my old K-20, it wasn't cost effective even with the 2 trans. in my yard. bk2life pretty much hit it. It can be a straightforward swap IF you have means to adapt or acquire the turbo 400 transfer case.

the turbo 350 and 400 do have different output shafts, size (may need driveshafts "adjusted") and the adapter.

When I looked into it, it was more cost efficient to have the turbo 350 built to what I wanted, though if you have a donor vehicle with the turbo 400 drivetrain....
__________________
'86 C-30 dually, 454/tbh400
'73 K-20 350/350/205 (sold )

I'm kinda like duct tape- no real purpose, but handy to have around.
donut is offline   Reply With Quote
Old 12-18-2012, 06:57 AM   #5
K30_dump
Registered User
 
Join Date: Oct 2007
Location: Pennsylvania
Posts: 164
Re: th350 to th400

Hello,

I agree with the above, would be more cost effective to have the TH350 built .

To swap to a TH400, you'd also need to wire an electric kickdown switch. Original switch was part of the gas pedal, but some aftermarket installs use a carb-mounted switch.

Being a '78, I'm assuming you have a 203 transfer case now. As mentioned, the adapter and input shaft on the case would need to be changed and they are RARE. You'd also need the correct output shaft in the transmission, as the 203 takes the shortest of all TH400 tail shafts (also extremely rare). Advance adapters may have a solution, not sure...

Either way, the TH350 can easily be built to take big block torque. Heck, my Dad ran one behind a 454 for many years in his K30 T-tag. That weighs 6,800 lbs and the transmission held up for nearly 20 years .

Hope this helps,

Joe
Posted via Mobile Device
K30_dump is offline   Reply With Quote
Old 12-18-2012, 11:20 PM   #6
Rubble
Registered User
 
Join Date: Feb 2012
Location: Big Valley. Alberta
Posts: 674
Re: th350 to th400

I don't know why not having a lift makes any difference,pulled a 700R out of my 85 K20 last year no lift.Just had to jack rear end up a bit to get tranny out from under truck on tranny jack.Sometimes you just have to be creative....
Posted via Mobile Device
__________________
1977 Chev C30 454/465/14ff DRW
1974 Chev C20.350/465/14ff

" Rock n Roll ain't noise pollution"
Rubble is offline   Reply With Quote
Reply

Bookmarks

Tags
th350, th400, tranny, transmission


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 12:02 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com