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View Poll Results: Trans and rear
TH350/12bolt
15
17.86%
TH350/9inch
11
13.10%
TH400/12bolt
19
22.62%
TH400/9inch
39
46.43%
Voters: 84. You may not vote on this poll

TH350/12bolt VS TH400/9inch

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Old 07-30-2006, 12:43 PM
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Default TH350/12bolt VS TH400/9inch

I want a drive train the handle high 9s/ low 10s. Launch hard enough to pull the front tires at least a foot or two. Trans brake. At least 33 spline spool. Car will almost be full weight.
Old 07-31-2006, 10:33 PM
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No takers?
Old 08-01-2006, 11:15 AM
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When in doubt, Overbuild. T400 and 9" are prolly overkill for the time you want to run, but it leaves you plenty to build on and go faster without having to rebuild the drivetrain again



When we put the rear in my buddies H/C LT1 car, we put in a 9" cause we new eventually, it would be big inch, T400 and a big shot of juice. Start at the rear, and build forward, make it bulletproof, and save you self time and $$ in the long run.


Just my $.02

Last edited by Dutch SS; 08-01-2006 at 01:33 PM.
Old 08-01-2006, 11:26 AM
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Personally i went with TH350 and the 12 bolt Strange for my setup. I think the 12 bolt Strange can handle either tranny, auto's are more forgiving obviously, but that doesnt mean they havent been broke. The weight saved with the 12 bolt and TH350 over a TH400 and 9" was considerable, along with the cost.
Old 08-01-2006, 12:52 PM
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Redline2K's car has a 400 and a 12blt. Car is full weight 3950#'s on 28" slicks, pulls 1.40 60's on the back tire. It's a moser with the true-trac unit in it with 33spl. If that helps you.
Old 08-01-2006, 02:42 PM
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Id go 9" for ease of gear swaps.
Old 08-01-2006, 08:29 PM
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Originally Posted by ApacheDrill
The weight saved with the 12 bolt and TH350 over a TH400 and 9" was considerable, along with the cost.
How much weight are we talking?
Old 08-01-2006, 08:30 PM
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How much difference in parasitic loss is there? Any ideas?
Old 08-01-2006, 08:50 PM
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I am not 100% sure off the top of my head i would say the th400 is 30 lbs heavier then a th350 and close the same with the rear ends maybe more..

There is also some HP loss through the Th400 and 9" rear.. but whats 15 to 20 HP to a car putting bigger number down...

The Cost is where it really adds up, im not even going to take a shot at it, but run a price list and see the difference between both setups.. In my case i did the rear suspension and the drive shaft at the same time.. add that into the deal if you havent already.. Hope that helps
Old 08-01-2006, 09:10 PM
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60+ lbs and 15-20 hp loss = -.2 -.3 in the 1/4.
Old 08-01-2006, 11:37 PM
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Just add more power to make up for it
Old 08-02-2006, 10:59 PM
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Originally Posted by gd1996
Id go 9" for ease of gear swaps.
I'd say it is a pain in the rear, to take out the center section in a F-body with the torque arm.
Old 08-03-2006, 01:20 AM
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Maybe a pain, but you can have an extra pumpkin setup already with other gears vs having to install and setup in the rear. Working on a bench is much easier.
Old 08-03-2006, 01:49 PM
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one of the biggest advantages with the 400 is there is a whole family of gear ratios for it.
Old 08-03-2006, 09:19 PM
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True but same with a 350 if you run a Coan 3 speed. I think Coan has 48 1st and 2nd gear ratio's with the Coan 3 speed(th350 based).
Old 08-05-2006, 12:55 PM
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I see tci and others sell the th400s wth a 2.75 first gear... but add 300 bucks for it.
Old 08-27-2006, 09:29 PM
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I am gonna go with a TH350 and a 9 inch.
Old 09-11-2006, 09:04 PM
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I went with a th400 rev body with brake and a 9 inch, I know im going to loose a couple of HP but its worth it to me to know that its going to hold up for a long time. your looking at a lot of money to do everything, a trans and converter ( a good one) will be around 2500, + you need a shifter, drive shaft, crossmember, if you get all goos stuff there you looking at 1000 so thats 3500 just for a trans, a rear is 2500 + you need a torque arm if you put a 9 inch in if you dont already have one, you need a spohn or BMR that has the holes for the 9 inch that are drilled out further, that 400 so for just a rear and trans your looking at around 6500 bucks.
Old 09-11-2006, 11:01 PM
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Well, I don't know about the weight difference or the HP loss, but a TH400/12 bolt just got me a 10.98 @ 125 MPH yesterday on my 347 CI engine N/A. I'd hate to think that there is a .2 to .3 ET loss in this from a TH350 or even a HP loss for that matter.

Dan
Old 09-11-2006, 11:51 PM
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what about a dana s60 rear end from strange? i love it


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