Automatic Transmission 2-Speed thru 10-Speed GM Autos | Converters | Shift Kits
Sponsored by:
Sponsored by:

th350 or th400. help

Thread Tools
 
Search this Thread
 
Old Mar 22, 2009 | 04:58 PM
  #1  
LSXFORMULA99's Avatar
Thread Starter
TECH Resident
15 Year Member
Photogenic
iTrader: (12)
 
Joined: Nov 2007
Posts: 873
Likes: 1
From: Alton IL.
Default th350 or th400. help

i have a m6 now and want to go with a auto

i would rather go with a th350 but u guys tell me. the car makes 410hp on motor and with spray no more than 600 at the wheels.

what all would it take to change my car over to one of these. i have been searching for like 3 years lol and cant find what all i need.
Reply
Old Mar 22, 2009 | 05:36 PM
  #2  
jmill96Z's Avatar
10 Second Club
iTrader: (3)
 
Joined: Feb 2006
Posts: 2,554
Likes: 1
From: Movin' On Up
Default

It all depends on the build. My car works great with the TH350, but I don't make a ton of power. I also footbrake the car, so it's not feeling quite the shock of the trans brake. It's a fairly simple swap.

Here's a quick list of what you'll need:

Tranny
Convertor
shifter assembly
Flexplate (get the sfi if you ever plan on going 9's)
Driveshaft (depending on whether you use a short or long tail shaft)
Cross member
Tranny cooler
Wire your speedometer into the front wheel sensor if you want to be cheap
Tranny blanket (if you plan on running 10's)

That's about all I can think of for now.
Reply
Old Mar 22, 2009 | 06:17 PM
  #3  
LSXFORMULA99's Avatar
Thread Starter
TECH Resident
15 Year Member
Photogenic
iTrader: (12)
 
Joined: Nov 2007
Posts: 873
Likes: 1
From: Alton IL.
Default

ok thanks alot man..do u think a built 350 would holad a decent amout of power
Reply
Old Mar 22, 2009 | 08:52 PM
  #4  
jmill96Z's Avatar
10 Second Club
iTrader: (3)
 
Joined: Feb 2006
Posts: 2,554
Likes: 1
From: Movin' On Up
Default

I'm gonna find out this year. I should be close to 750ish on the spray. Hopefully it will hold up.
Reply
Old Mar 22, 2009 | 09:07 PM
  #5  
gsxr1k2's Avatar
12 Second Club
iTrader: (6)
 
Joined: Jul 2007
Posts: 399
Likes: 0
From: A Mile High
Default

I run close to that hp. I'm running a built th400 which is alot of overkill but I plan on going to bigger and better things. Searching for three years????? **** i looked at the stickys and sent some pm's and BAM bobs your uncle it was in my 01 camaro.

Cost me around 1800 complete. Found a th400 on tech along with a converter and the rest- cooler, crossmember, flexplate, shifter from sponsers on here.
Reply
Old Mar 23, 2009 | 02:26 PM
  #6  
First Collision's Avatar
10 Second Club
iTrader: (13)
 
Joined: Mar 2006
Posts: 227
Likes: 0
From: Baytown, TX
Default

I would go TH400 and be done with it, but that's just me and I only like doing things once, lol. Also leaves room for bigger and better things, because nothing is ever fast enough.
Reply
Old Mar 23, 2009 | 02:31 PM
  #7  
cgslow77's Avatar
On The Tree
iTrader: (2)
 
Joined: Oct 2008
Posts: 191
Likes: 0
From: Ohio
Default

ya, a built th350 will handle that, i just built mine and its holding my 6.0 lq4 on nitrous with out a problem.... talk to dana from probuilt... 700r4l60e.com
Reply
Old Mar 23, 2009 | 06:06 PM
  #8  
firefighting1101's Avatar
TECH Resident
iTrader: (48)
 
Joined: Sep 2007
Posts: 963
Likes: 0
From: Miami, FL
Default

i went with a ATF Speed th400. fully built for 1250hp with a brake for $1650 BRAND NEW! IM RUNNING IT IN A 550rwhp and anther 350 on spray
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

6 Gifts Neither Your Dad Nor Grad Will Shove Into the 'Trinket Drawer'

 Brett Foote
story-1

Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

 Pouria Savadkouei
story-2

Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

 Verdad Gallardo
story-3

7 Most Reliable High-Performance Engines GM Has Ever Built

 Verdad Gallardo
story-4

Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

 Verdad Gallardo
story-5

6 Common C5 Corvette Failures and What's Involved In Repairing Them

 Pouria Savadkouei
story-6

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

 Verdad Gallardo
story-7

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-8

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-9

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
Old Mar 23, 2009 | 06:44 PM
  #9  
Bersaglieri's Avatar
TECH Resident
iTrader: (13)
 
Joined: Aug 2007
Posts: 768
Likes: 0
From: Wild West
Default

Originally Posted by cgslow77
talk to dana from probuilt... 700r4l60e.com
I highly advise people to stay away from Dana @ Pro Built. Stick with a well known builder with years under their belt. ATI is a big name, Rossler is too. Frank @ CPT seems to do well, although sometimes he's behind of schedule. Just dont do Pro Built, I cant stress this enough. I wonder if I'll ever get my transmission back...it's getting close to two years...

I'd go TH400 if your going to be spraying alot. My buddy was breaking TH350's left and right till he went TH400. There's always the 4L80e if you like to street drive alot.

-Dustin-
Reply
Old Mar 23, 2009 | 07:07 PM
  #10  
LSXFORMULA99's Avatar
Thread Starter
TECH Resident
15 Year Member
Photogenic
iTrader: (12)
 
Joined: Nov 2007
Posts: 873
Likes: 1
From: Alton IL.
Default

ok then i will go with the th400. how much of a difference of power loss at the wheels is there from the 350 and 400.
Reply
Old Mar 23, 2009 | 11:47 PM
  #11  
Bersaglieri's Avatar
TECH Resident
iTrader: (13)
 
Joined: Aug 2007
Posts: 768
Likes: 0
From: Wild West
Default

Just from the trans itself, not too much, of course you'll lose some with a converter depending on how loose it is. Auto cars cant be dyno queens like manuals can, the quarter mile is where they shine.

-Dustin-
Reply
Old Mar 24, 2009 | 05:31 AM
  #12  
Z28/2002's Avatar
11 Second Club
iTrader: (27)
 
Joined: May 2005
Posts: 6,799
Likes: 5
From: Your girl's back door giving her the long stroke while you're at work
Default

I had enough money to do the swap once I sold my T56, clutch setup and shifter. I went with a TH350 because I can get them built to the hilt for a decent price(I know the shop owner).
Reply
Old Mar 24, 2009 | 06:24 PM
  #13  
rmata's Avatar
TECH Regular
iTrader: (34)
 
Joined: Mar 2004
Posts: 423
Likes: 0
From: Corpus Christi, TX
Default

You'll also need a dipstick as well. Madman makes one at a good price. I have my old nitrous converter for a th400 I'll let go for real cheap. Just send me a pm for more details if you're interested.
Reply
Old Mar 24, 2009 | 06:32 PM
  #14  
LSXFORMULA99's Avatar
Thread Starter
TECH Resident
15 Year Member
Photogenic
iTrader: (12)
 
Joined: Nov 2007
Posts: 873
Likes: 1
From: Alton IL.
Default

yeah i would rather be faster at track than make bigger dyno numbers. i already made 410/406 with my m6, after i do the swap i can still say i made those numbers. lol i doesnt matter really...

what flex plate would i use??
Reply
Old Mar 24, 2009 | 06:35 PM
  #15  
Z28/2002's Avatar
11 Second Club
iTrader: (27)
 
Joined: May 2005
Posts: 6,799
Likes: 5
From: Your girl's back door giving her the long stroke while you're at work
Default

I went with the TCI flexplate but Speed Inc has one also
Reply
Old Mar 24, 2009 | 10:15 PM
  #16  
DopdBrd's Avatar
TECH Addict
iTrader: (25)
 
Joined: Nov 2004
Posts: 2,529
Likes: 0
From: Garden City, KS
Default

I'm looking to do the same thing. Buddy of mine has a built TH400 with a Transbrake and reverse full manual valve body. He was running it in his Twin Turbo'd Firehawk and never had a problem with it. Said I could have it for 600.

So if I have this right, I will only need a driveshaft, shifter, cooler, flexplate and convertor right? I already have a BMR torque are that is relocated off the tranny and he said I can use the 6 speed crossmember. Sorry for the highjack!
Reply
Old Mar 25, 2009 | 02:16 PM
  #17  
Z28/2002's Avatar
11 Second Club
iTrader: (27)
 
Joined: May 2005
Posts: 6,799
Likes: 5
From: Your girl's back door giving her the long stroke while you're at work
Default

You got it basically covered
Reply
Old Mar 26, 2009 | 07:27 AM
  #18  
cgslow77's Avatar
On The Tree
iTrader: (2)
 
Joined: Oct 2008
Posts: 191
Likes: 0
From: Ohio
Default

what are your plans for that 6 speed your taking out?
Reply
Old Mar 26, 2009 | 07:50 AM
  #19  
mad_steve's Avatar
TECH Fanatic
iTrader: (2)
 
Joined: May 2008
Posts: 1,073
Likes: 1
From: TEXAS
Default

We have dipsticks with tubes for th400, th350, and powerglides. They are all $71.70 plus shipping. Call me to place your order.
Reply
Old Mar 26, 2009 | 08:20 AM
  #20  
Z28/2002's Avatar
11 Second Club
iTrader: (27)
 
Joined: May 2005
Posts: 6,799
Likes: 5
From: Your girl's back door giving her the long stroke while you're at work
Default

Wish I would have bought one of the Madman dipsticks instead of the Lokar I have
Reply



All times are GMT -5. The time now is 03:52 PM.

story-0
6 Gifts Neither Your Dad Nor Grad Will Shove Into the 'Trinket Drawer'

Don't get dad new socks or a grill brush this year.

By Brett Foote | 2026-06-04 18:13:20


VIEW MORE
story-1
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

Slideshow: We take a close look at the ONE and Artidiag 800BT2 diagnostic tools from Topdon and the reasons to buy one over the other.

By Pouria Savadkouei | 2026-05-28 11:05:11


VIEW MORE
story-2
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

Slideshow: The controversial Ferrari F6 swaps its original flat-12 for a Corvette Z06-derived LT4 V8 and sends power to four rear wheels through a custom-built drivetrain.

By Verdad Gallardo | 2026-05-26 18:23:54


VIEW MORE
story-3
7 Most Reliable High-Performance Engines GM Has Ever Built

Slideshow:These GM engines didn't just make huge power, they survived abuse, boost, track days, and six-digit mileage with a reputation for refusing to quit.

By Verdad Gallardo | 2026-05-21 16:45:27


VIEW MORE
story-4
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-5
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-6
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-7
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-8
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-9
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE