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Old 05-15-2015, 07:29 AM   #1
Braveheart
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what's involved in switching my T350 to a T400 in my 71 K5?

Anyone no what is involved in switching my T350 to a T400 Tranny in my 71?
I thought i saw a thread on this but cant seem to locate it. Thanks.
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Old 05-15-2015, 09:59 AM   #2
praisegeetarman
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Re: what's involved in switching my T350 to a T400 in my 71 K5?

Special tail shaft for the T400, move the transfer case back, longer front drive line, shorter rear drive line, add electric kickdown switch. That should be it.

hope this helps,

Keith
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Old 05-16-2015, 07:55 PM   #3
Braveheart
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Re: what's involved in switching my T350 to a T400 in my 71 K5?

big help thanks. where do i get the special tail shaft?
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Old 05-16-2015, 10:56 PM   #4
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Re: what's involved in switching my T350 to a T400 in my 71 K5?

Quote:
Originally Posted by Braveheart View Post
big help thanks. where do i get the special tail shaft?
Here is the adapter kit.

http://www.advanceadapters.com/produ...50adapter-kit/

Spendy, but the turbo 400 is bullet proof. A well built turbo 350 will do for light four wheeling.
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Old 05-18-2015, 06:57 AM   #5
Braveheart
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Re: what's involved in switching my T350 to a T400 in my 71 K5?

Thanks for that link! It says a TH350 coupler is also needed but i don't see that listed.
I put a 500+ HP 496 in my K5 and even with a built TH350 it can't take it. I think it's worth the $$ to go with the TH400. will save allot of headaches and down time. As far as being "spendy" I'm so deep into this truck already it doesn't matter
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Old 05-18-2015, 02:34 PM   #6
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Re: what's involved in switching my T350 to a T400 in my 71 K5?

You can buy a built 2004-r from Monster and you wouldn't have to buy new front or rear driveshafts, or move your t-case.

http://www.monstertransmission.com/2...l#.VVowWvlVhBc
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http://67-72chevytrucks.com/vboard/s...d.php?t=663780
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Old 05-18-2015, 04:01 PM   #7
praisegeetarman
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Re: what's involved in switching my T350 to a T400 in my 71 K5?

Quote:
Originally Posted by Braveheart View Post
Thanks for that link! It says a TH350 coupler is also needed but i don't see that listed.
I put a 500+ HP 496 in my K5 and even with a built TH350 it can't take it. I think it's worth the $$ to go with the TH400. will save allot of headaches and down time. As far as being "spendy" I'm so deep into this truck already it doesn't matter
If you have a TH350 in there now you already have the coupler.

Good luck with your project.

Keith
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Old 05-20-2015, 06:37 AM   #8
Braveheart
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Re: what's involved in switching my T350 to a T400 in my 71 K5?

thanks for this info. the "monster" tranny seems like the way to go
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Old 05-21-2015, 10:50 AM   #9
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Re: what's involved in switching my T350 to a T400 in my 71 K5?

You can move the engine forward as well. I've seen many go this route rather than moving the transfer case. Keeps your drive lines in the same place as well as your shifter.
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Old 05-26-2015, 12:08 PM   #10
PGG
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Re: what's involved in switching my T350 to a T400 in my 71 K5?

I like the idea of swapping to an overdrive tranny. I can barely run 70 mph on the freeway and it would help mileage too I guess. I might wait until I need the engine rebuilt but this is my thought for the future on mine.
That link to Monster shows a suggestion to the 700R for high horsepower engines.
What would a 305-700R swap take?
Do yall think it would lower the value much of a fully original 1972 CST like I have?
I guess I could always save the 350 for later in case I ever sell it.
Thanks PG
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Old 05-27-2015, 02:55 PM   #11
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Re: what's involved in switching my T350 to a T400 in my 71 K5?

I wouldn't think it would affect the value because you don't modify anything other than moving the engine forward. The frame actually has the holes to do this so as far as I can tell there is no drilling. I was considering the swap but I have a rebuilt th350 and don't do much highway driving so I wasn't as concerned. Also have 3.08 gears so 65 isn't that bad.
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