Th400 swap bc i dont want to do it twice.

[Wahoo]

So my car is an 85 t type, that isnt fast yet, but i plan to make it as fast as i can when money allows.

Its also a salvage title car so its not going to be worth a lot to most people, probably wont get any money back if i sell it one day.

So the deliema is the tranny is slipping and i feel like id rather run a th400 because i know it will be the strongest tranny to build once i need the strength.

I dont need mpg, or drive it far distances. Im debating on lightening up the car as well, but not going to hank it up. Its not gonna be a daily driver, its going to be for drag racing, not a race car though, at least for a little while.

I just want to not worry about the tranny any day soon.


Any thoughts from the people who have done the swap?

Thx

 

[pacecarta]

youve read the threads...
for the th400 swap you need new converter , shorter drive shaft with a th400 slip yoke , a BOP case TH400trans (built for your hp level and with the cooler restriction) reverse manual valve body if higher hp (constant pressure ) and that would include a transbrake for which you should run a trans blanket or shield for safety (required at track) , as well as a shifter gate or an aftermarket shifter for 3speed trans ..
if you were after 9s or 8s in the 1/4 then the th400 would make sense .. but at 15 second power.. stick with the 2004r

 

[Wahoo]

youve read the threads...
for the th400 swap you need new converter , shorter drive shaft with a th400 slip yoke , a BOP case TH400trans (built for your hp level and with the cooler restriction) reverse manual valve body if higher hp (constant pressure ) and that would include a transbrake for which you should run a trans blanket or shield for safety (required at track) , as well as a shifter gate or an aftermarket shifter for 3speed trans ..
if you were after 9s or 8s in the 1/4 then the th400 would make sense .. but at 15 second power.. stick with the 2004r

Well even if the car never runs 10s, wouldnt it cost less to get me there with a th400 then building the 200r4.

Remember my 200r4 is the crappy one because its for an 85.

Also my car is 13 second power if not high 12s lol, its a TA33, cutout, less restrictive air intake, 160 t stat, on e85 pushing 20 psi, if not more once i get a new boost gauge that works properly.

It just seems 200r4s arent that easy to build if you want to dyi, they need a lot of little modifications to get them to last. When you hire a builder they really need to know how to build them well, seems like not just anyone can build them.

Not that i know a lot about th400s, but they almost seem like you just install some hard parts and your good.

Id like to build mine. Id like to really lighten the car up. Depending how rebuilding the turbo v6 goes might only stick with it for a couple rebuilds if it doesnt last... So th400 would be able to hold whatever else i throw at it if the time comes.

 

[yullose]

Well even if the car never runs 10s, wouldnt it cost less to get me there with a th400 then building the 200r4.

Remember my 200r4 is the crappy one because its for an 85.

Also my car is 13 second power if not high 12s lol, its a TA33, cutout, less restrictive air intake, 160 t stat, on e85 pushing 20 psi, if not more once i get a new boost gauge that works properly.

It just seems 200r4s arent that easy to build if you want to dyi, they need a lot of little modifications to get them to last. When you hire a builder they really need to know how to build them well, seems like not just anyone can build them.

Not that i know a lot about th400s, but they almost seem like you just install some hard parts and your good.

Id like to build mine. Id like to really lighten the car up. Depending how rebuilding the turbo v6 goes might only stick with it for a couple rebuilds if it doesnt last... So th400 would be able to hold whatever else i throw at it if the time comes.

If you don't mind the loss of OD and you never want to crawl under the car to pull the transmission again... I'd say go for it.
I did the TH400 swap on two of my three Turbo Buicks. I loved the OD for cruising around, but I hate fixing things more than once. Even some of the best builders have had comebacks on their hi-dollar 200r4 builds. Just about anyone with a set of tools and a Chilton manual can build a reliable TH400.

 

[Wahoo]

I mean, im really trying to do it budget minded. So i do need to figure out the costs. Because ill need a converter, and a yoke and either new driveshaft or shorten my stock one.

Then probably a floor shifter, unless i make the th400 able to shift at the correct rpms.

 

[regan j]

I may be wrong, but,,, I have always been told a 400 is less efficient than a 350

 

[Wahoo]

I may be wrong, but,,, I have always been told a 400 is less efficient than a 350

I dont think it matters when you make enough power.

Im sure street outlaws a lot of them use th400s.

I dont care if its not as efficient, i inow its heavier, but id rather not have to rebuild it a millions times.

 

[INEEDAGN]

Remember my 200r4 is the crappy one because its for an 85.

I just want to point out that for a practical starting point for a performance build, there's very little difference between an 85 bq and a brf. Most of the things that are different are things that are replaced anyway

Don't blame you for going 400 if it's not a highway cruiser. But don't scrap the bq trans.

 

[3-5.0]

I remember way back when the GN'S were establishing a reputation it was all "but the 200 is the weak point and swapping a 700 is an upgrade", now, I think I've read it's the opposite. Trans tech seemed to do a 180 on what was once considered bad. What I'm generally pulling from this is it's what's on the inside that counts not some 40yr old hoodoo. To me putting a T400 in a higher tech late model musclecar is...it reminds me when guys were putting carbs on FI Foxes because they couldn't deal with the new fangled injection and it ended up being backyard redneck kill value day.

 

[GNBRETT]

wouldnt it cost less to get me there with a th400 then building the 200r4.

how do u figure that wen u need all the other parts to make the 400 work. just have the 200 built right and keep ur OD.

 

[Wahoo]

how do u figure that wen u need all the other parts to make the 400 work. just have the 200 built right and keep ur OD.

i really dont know, thats why im asking. Im trying to see if the people who have done the swap believe it to be a better choice.

I can get a th400 off craigslist, probably go through it and replace any worn items, install a shift kit and it wpuld probably take me to 11s. Although the oil pressure mod needs to be done as well to the th400.

Where a 200r4 would cost 3k to build and would maybe get me there or break once trying?


I just think it might be a good option.

 

[87GNSteve]

I understand the 400 causes excessive forward thrust on the crankshaft and eats the thrust bearing. There s a remedy but need to look into it.

 

[V6sleeper]

Go to the right 200 builder and it will be fine, you put a 400 in a 13 second car and you will be in the 14s, it eats up a lot more hp, guys running 9s can afford to loose 40 hp in a th400.

 

[kandc7]

i really dont know, thats why im asking. Im trying to see if the people who have done the swap believe it to be a better choice.

I can get a th400 off craigslist, probably go through it and replace any worn items, install a shift kit and it wpuld probably take me to 11s. Although the oil pressure mod needs to be done as well to the th400.

Where a 200r4 would cost 3k to build and would maybe get me there or break once trying?


I just think it might be a good option.

. A 200 has been in the 9s and even in the 8s... You get it built by a vendor on here it will run reliable to high 9s low tens. If your gona run low 9s most of the time than I go 400. Just my 02.

 

[Wahoo]

This thread is also about budget. Whats the cost of building a 9 sec 200r4 compared to a 9 sec th400?

I need a converter for either transmission.

I also feel a th400 is easier for a dyi'er to build himself, is this true?

 

[nonoss38]

all depends on the weight of the car. Yes,,some run fast with the 200. most are lighter than you think. 3300lbs vs 3700lbs is why they live at those power levels. Not saying the 200 is not a great trans but there are other factors you have to take account for.

 

[Wahoo]

all depends on the weight of the car. Yes,,some run fast with the 200. most are lighter than you think. 3300lbs vs 3700lbs is why they live at those power levels. Not saying the 200 is not a great trans but there are other factors you have to take account for.

I plan to try to lighten up the car, id like to install a fiberglass front bumper, and aluminum supports.

Might remove the AC, already have an fbody radiator which i think took a little weight off compared to the stock one.

I want to make the car fast, i dont plan to gut the car, but since my digital climate control doesnt work, i guess might as well remove the AC and figure a way to just have heat for defrosters.

Like i said this car is a salvage car, if i tried to sell it on this forum or anywhere, im sure people wouldnt want to pay much for it anyways, so id like to just make it perform the best i can, make it as strong as i can for as little money as i can.

 

[V6sleeper]

I plan to try to lighten up the car, id like to install a fiberglass front bumper, and aluminum supports.

Might remove the AC, already have an fbody radiator which i think took a little weight off compared to the stock one.

I want to make the car fast, i dont plan to gut the car, but since my digital climate control doesnt work, i guess might as well remove the AC and figure a way to just have heat for defrosters.

Like i said this car is a salvage car, if i tried to sell it on this forum or anywhere, im sure people wouldnt want to pay much for it anyways, so id like to just make it perform the best i can, make it as strong as i can for as little money as i can.

I wouldnt worry too much about the re-sale, most of us with 60k+ plus in our cars are lucky to get 40% back ..its the nature of the hobby, your gonna be upside down in the end no matter how you slice it...
just try to keep overhead down as much as possible and have a sure plan..

 

[turbobitt]

Some will claim the TH400 stuff can be built cheaply but I found over the years to do a really good job the case needs a decent amount of detail work to make it worthy of using. Finding good cores are getting harder to find as well. The bolt-on bell housing is crappy IMHO with no good way to positively locate it on the trans. CK came up with a nice adapter for the Reid bell housing but again a lot of extra $$$ for a stock street car. Probably not a very cost effective option and will take some fun out of a dedicated street car.

Depending on where your located I would seek out a supporting TH200R4 vendor for your needs.

 

[toofastforyou]

youve read the threads...
for the th400 swap you need new converter , shorter drive shaft with a th400 slip yoke , a BOP case TH400trans (built for your hp level and with the cooler restriction) reverse manual valve body if higher hp (constant pressure ) and that would include a transbrake for which you should run a trans blanket or shield for safety (required at track) , as well as a shifter gate or an aftermarket shifter for 3speed trans ..
if you were after 9s or 8s in the 1/4 then the th400 would make sense .. but at 15 second power.. stick with the 2004r

Paul, I read your post and it's almost a description of what Brian did to my car!… …TH4oo with converter, drive shaft mod, yoke, SFI bell housing and blanket, reverse manual valve body and transbrake , shifter gate, etc…Well worth it to have peace of mind when running in the 9's.

Claude