Just got it! TH400/Chevy350

Joined
Dec 23, 2004
Messages
146
Location
Fredericksburg ,TEXAS
I just bought a 1985 Chevy 1 ton Van with a fresh TH400 trany and a 350 with 25k on it. $500

Has anyone put the TH400 in a FJ40 along with the 350?

Also could the power steering be used as well?
 

Fireman

 
 
Joined
Sep 5, 2003
Messages
5,451
Location
Iowa Park. TX
Where in Texas are you. Its been doon plenty of times, adapter to stock transfer case is the biggest expense. Rear driveshaft can get a little short for some folks taste.
 
Joined
Oct 11, 2004
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1,773
Location
tunica, ms
very nice, is that a tbi engine? i've been wanting to go auto for some time now, but just can't force myself. i know that setup has been done plenty. try searching it.
 
Joined
Feb 17, 2002
Messages
64
Th400/sbc

I've got this combination in my 68 FJ40. I also went to Saginaw PS.
Mine has the original 3 speed Xfer case.
All of my adapters/mounts are AA. I used a Hurst shifter and it works OK but I'd consider a Lokar now. I did my years before Lokar was around.
Like the other guy said the rear ds is short but I have about 10k miles on my conversion and it's held up under normal 4x4 and street use.
I also used both rear mounts: The Xfer case mount and also the tranny mount.
You could get by with either one, I think 2 are overkill. The tranny mount is cleaner.
I offset my engine about 1 inch to the passenger side to help with steering shaft/exhaust manifold clearance.
I had to slightly notch the tranny pan for clearance for the front ds U-joint. Some guys have modified the yokes/ujoints to get around this. Notching the pan is easy fix.
I also had to notch the gas tank for Xfer case shifter clearance. I could have done it differently but welding sheet metal is easy.
I have a low-stall torque converter and have excellent engine braking. I use it in the mountains elk hunting and it goes where the big pickups and Jeeps can't make it.
I'd recommend getting a good radiator/fan system. I am running a 4 core with flex fan and tranny cooler in front of radiator. That's OK here in Wyoming but for any warmer climate I'd run a seperate tranny cooler/ an electric fan, like the Taurus fan and maybe a bettter radiator, like a BeCool or Griffin.
Hindsight is 20-20 and if I did it all over, I'd have an overdrive automatic. The extra gear would get the RPM down when running the highway. But if you're like me and only drive it occasionally, gas mileage doesn't matter that much.
I have a lot of pictures of the conversion, Let me know if you'd like to see them.
Paul
Evanston, WY
 

Gumby

Supamod
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Joined
Dec 13, 2002
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11,678
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Knee deep in hookers and gin
I just got back from wheeling mine for the first time today.

During the 1.5 hour drive there it was painfully obvious that I had a 1:1 third with 4:10 axle gears. I couldn't tell speed because my marlin speedo extension hasn't arrived yet, but I was keeping up with traffic OK.

On the trail the 400 was great.

I went with the NP203 doubler kit. It adds a little, but very little length compared to an aapter. 4:1 with the 400 is pretty flippin cool. I just put both cases in low and wheeled in drive until I wanted to crawl, then dropped down into first.

Carbs suck ass. I'm headed into the shop after 17 hours yesteday and two more hours before leaving this morning to switch intake manifolds. The Edlebrock is not going to work for tomorrow. A Quadrajunk is going on until I go TBI this winter.
 
Joined
Feb 27, 2002
Messages
2,894
Gumby said:
I just got back from wheeling mine for the first time today.

During the 1.5 hour drive there it was painfully obvious that I had a 1:1 third with 4:10 axle gears. I couldn't tell speed because my marlin speedo extension hasn't arrived yet, but I was keeping up with traffic OK.

Ditto, on my old V8 60, i would've given anything for a 700R4 overdrive tranny, and that's why I sold the truck. Wound up as all hell at 70 mph, even with 33's. Sell/trade the TH400 unless you're going primarily offroad...
 

Fireman

 
 
Joined
Sep 5, 2003
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5,451
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Iowa Park. TX
My 700R4 behind a 400 sbc, 4:11, and 35 tires turns ~3k at 70 mph. Love the overdrive compared to the old 3 speed manual!
 
Joined
Nov 1, 2009
Messages
4
Location
Ashford, WA
pfry pics

Hey pfry! I would like to see those pics of your pan notch. I have a TH400 in my '73 FJ40 and am getting ready to put it back in. The previous owner just installed everything, put it in 4WD, andbeat the heck out of the pan. Then couldn't figure out why the pan always leaked and sold it to me for a song. Anyhow, I've got some marks on the pan where I think it should be cut, but wanted to see what you did to make sure I am headed down the right path. if email would be easier let me know. Thanks
 

Downey

 
Joined
Jun 5, 2007
Messages
4,259
Location
Brea, Calif.
TH400 is radically long and radically over-kill. I'd trade the b--ch for a 700R4 just to get:
(a) a shorter tranny and longer drive shaft
(b) a lower first gear than the 400 has
(c) an overdrive high gear the 400 doesn't have
Then use my shorter 1" thick adapter to your transfer-case just to keep the rear drive shaft longer. AA and I also sell a smaller front u-joint with long travel slip yoke so that you don't have to cut and weld the tranny oil pan. I don't know why guys still do that?????
 
Joined
Nov 1, 2009
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4
Location
Ashford, WA
Well, considering a)I just had the 400 rebuilt, b)I actually have the 400, c) I was a steel/sheet metal fabricator for over a decade and d)the beast is already set up for the 400, I think I will stay with the 400. I am not arguing that the 700R4 doesn't have all the other goodies/benefits. Just not the right time for me.
 
Joined
Mar 14, 2006
Messages
1,016
Location
Belfair, Wa
I have the 350/TH400 combo as well. Originally had the stock wheelbase, and although the rear drive shaft was kinda short, never had issues with it. Notched the pan for clearance as well. I have a radiator out of some Chevy car and a clutch fan, works great. If it was a daily driver, it would be nice to have the overdrive, but as it is mainly a "fun" vehicle, the 400 works great. So I guess it depends on your main use for it. Which ever route you choose, ENJOY, and post pics of your build:beer:
 

Downey

 
Joined
Jun 5, 2007
Messages
4,259
Location
Brea, Calif.
Well, considering a)I just had the 400 rebuilt, b)I actually have the 400, c) I was a steel/sheet metal fabricator for over a decade and d)the beast is already set up for the 400, I think I will stay with the 400. I am not arguing that the 700R4 doesn't have all the other goodies/benefits. Just not the right time for me.
No sweat!! My point was if a guy didn't already have the tranny bought and paid for, then by all means consider the 700R4!!
 
Joined
Nov 1, 2009
Messages
4
Location
Ashford, WA
I would. And sometimes I stumble across things like engines and transmissions, so if a 700-r4 ever popped up I would consider swapping it in place oif the th400.
 
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