TH400 swap

crossmember is fine

trans mount can use the 200r4s with some notching to widen the holes , or if you want easy and to go poly get the hrpartsnstuff TH400 mount kit

driveshaft about 1" short of stock , will end up being 50.5" ctr to ctr of joints but measure what you have once its in

the 200 yoke wont work (works for th350) , yoke needs to be for the th400

trans lines will bolt up with minor rebending, or easy but not cheaper go to braided -6AN

400 trans has to be a BOP (buick olds pontiac) bellhousing pattern or you could cut the bellhousing back and go with an ultrabell SFI bellhousing

speedo cable will work , you'll need the right speedo gears selected based on tires and rear ratio

you'll need dipstick from a TH400 or a Lokar flexible braided dip tube assembly available in locking or std

the shifter gate can be replaced with one cut out for a th400 (not sure who has these now)
or choose an aftermarket shifter ,
you'll need a th400 shifter linkage arm for the trans (comes with aftermarket) , you can cut off and use the column linkage portion of your 200s arm so that you still have reverse lights and column lock

you'll need a torque converter for th400 ,
 
I still have my GN's original 200-4R transmission on the car which was built by the late Eric Shertz of Dynotech, using all the "bullet-proof" parts money can buy, including a Performance Transmission's "Bat Brake". It was quite expensive ($3,500. 7-8 years ago !), but it never broke, always performed flawlessly. I never had the slightest problem with it, BUT that was with my 3.8 aluminium block TA motor with M&A heads, running a personal best of 10.51 @ 129 mph. Now that I have a Stage II 4.1 RPE "badass" motor in the car, Jack Cotton keeps telling me that it's just a matter of time before the 200-4R breaks, that it won't live very long running in the 9's launching a 3,600 pounds car using a trans-brake, and that I should seriously consider converting to a TH-400... At first, I didn't even want to hear about going to a "400", but now, after listening to Jack's explanations, I'm starting to change my view on this and if everything goes well this year, I might go to a TH-400 swap during next winter, we'll see...There are a few things which bother me a bit about going with a TH-400...which are the fact that it doesn't have any overdrive, and also, all of the ones I've seen to date that had a trans brake had a manual reverse pattern valve body which I don't find very conveinient when driving the car on the street, but Jack says that not having an overdrive isn't that bad and the "reverse pattern" thing isn't that bad getting used to either. I already have a B&M "Pro Stick" shifter in my car, so the only thing I'll have to do will be to change the gate plate for a 3 speed reverse pattern tranny (B&M pt#80710). There'll also be a few changes in the crossmember area, driveshaft lenght and front yoke, dipstick, speedo gears, a torque converter, etc...but that'a about it. Brian Cotton has done a few of these swaps already, so he should know what's needed. :wink:
Last, I've spoken to Jack about using a 4L80E (which is a TH-400 with an overdrive), but he doesn't recommend this, saying that most guys who used them had problems with them...:rolleyes:

Claude. :smile:
 
In about a year you will need a crank for your motor. The th400 will wear our the thrust bearing fast. The front pump needs to be modded to lower the pressure. Pm donwg because he can explain it better. Or search "th 400 thrust bearing"
 
column shifter rod..

How do you gauge the length of the rod,
to keep column shift (i like stealth)?
I notice the rod sticks through the grommet but doesn't conflict with the frame, why is it necessary to shorten the rod?
Gary
 
And another discovery..
Don't forget to open up the converter bolt holes if you plan on using ARP Fasteners (230-7302)

Yep.. I missed that little tidbit of info (till) trying to shove the bolt through the mounting flange.
Funny, JW doesn't mention this either with
"THE WHEEL" :( such a deal.
 
This seems like it should be a sticky, hard to find good th400 info.
 
I did the swap . I welded the rod to my B@M bracket so it still works .
image.jpeg
 
Here is the pic of he bracket I welded to maintain the colum shift
image.jpeg
image.jpeg
 
If you want a passing gear, you will need to wire up a switch or use a Lokar TH400 passing gear unit.

Has anyone ever run a PowerGlide?
 
Not wishing a bashing but seems the th400 although a good trans is a step back . The 200 is much more suitable for the tr .
 
It is a matter of torque handling capacity. The TH400 is a much stronger trans.
 
I agree the th 400 could get more power to the pavement . The 200 in the tr as a package if built correct can and has constantly put power to pavement with the limits of the v6 power . It just seems a lot more work and money to adapt the 400 . The 4 l 60 is another matter.
 
I still have my GN's original 200-4R transmission on the car which was built by the late Eric Shertz of Dynotech, using all the "bullet-proof" parts money can buy, including a Performance Transmission's "Bat Brake". It was quite expensive ($3,500. 7-8 years ago !), but it never broke, always performed flawlessly. I never had the slightest problem with it, BUT that was with my 3.8 aluminium block TA motor with M&A heads, running a personal best of 10.51 @ 129 mph. Now that I have a Stage II 4.1 RPE "badass" motor in the car, Jack Cotton keeps telling me that it's just a matter of time before the 200-4R breaks, that it won't live very long running in the 9's launching a 3,600 pounds car using a trans-brake, and that I should seriously consider converting to a TH-400... At first, I didn't even want to hear about going to a "400", but now, after listening to Jack's explanations, I'm starting to change my view on this and if everything goes well this year, I might go to a TH-400 swap during next winter, we'll see...There are a few things which bother me a bit about going with a TH-400...which are the fact that it doesn't have any overdrive, and also, all of the ones I've seen to date that had a trans brake had a manual reverse pattern valve body which I don't find very conveinient when driving the car on the street, but Jack says that not having an overdrive isn't that bad and the "reverse pattern" thing isn't that bad getting used to either. I already have a B&M "Pro Stick" shifter in my car, so the only thing I'll have to do will be to change the gate plate for a 3 speed reverse pattern tranny (B&M pt#80710). There'll also be a few changes in the crossmember area, driveshaft lenght and front yoke, dipstick, speedo gears, a torque converter, etc...but that'a about it. Brian Cotton has done a few of these swaps already, so he should know what's needed. :wink:
Last, I've spoken to Jack about using a 4L80E (which is a TH-400 with an overdrive), but he doesn't recommend this, saying that most guys who used them had problems with them...:rolleyes:

Claude. :smile:
Claude.
You know I have done this already. I complained about everything. That's what I do! I just complain. If I didn't complain, I wouldn't be me.;)

But, in the end, it turned out just fine. We had a few bumps in the road during the install. The new dip stick was a pain in the ass to get in. The trans sprung a leak 3 minutes after it started, the drive shaft was high jacked from the "Great Pumpkin" and it was a hair too short, the speedo gears were never installed in the tail shaft of the 400. Non of this was Jack's fault. It just happens like this sometimes. No big deal though.

Other than that stuff........I'm happy. You know I drive it everywhere and don't miss OD at all. I have the SFI bell housing, a sheet metal aluminum pan, an additional auxiliary external Tilton pump with a secondary cooler and fan. And the most important feature for street driving, a smooth acting reverse pattern B&M ratchet shifter.
 
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