i am thinking of swapping out my th350 transmission in my 69 firebird to a 2004r or similar tranny,iwas wondering if anyone else has done this swap or something similar and what is involved in doing so.i have read that the 2004r is an almost direct replacement.anything would be much appreciated,thanks allen
several of my friends have done it...they like it....I have not yet done the swap...trying to figure out how many miles I`ll drive before the gas savings pays for itself...I thionk I can drive many miles before a swap pays for itself...of course ea time I fill up, I think about it... its like 'pay me now or pay me as you go'...lol
I heard of issues with the strength of the 200r4. Alot of power equals tranny failure... If you are building a driver car this should not be an issue. Sure you can have one built to withstand some torque or power. Doesn't the 200r4 have a lock-up style converter?
They are now building 200r4 that can withstand over 500hp. My friend just put one in a 80 T/A with a built 455 pushing right around 500hp and the 200r4 he installed handles the hp with no problem.
I am with Bjorn on this one. With the cost involved, a person would have to drive their car like we do, daily in order to recover the expense. I see people do this stuff all the time, as well as the Tremac conversions etc. unless you plan on driving across country, how will you possibly recoupe the exepense?
The nice thing about the overdrive is not only does it improve mileage (although as others said, will probably not enough to pay back unless you drive it daily), but it makes it more enjoyable to drive on the highway (less noise), and reduces wear and tear on the engine. Plus with something like the 2004R, the first gear ratio is deeper giving you a better off the line launch.
Allen, I've done this swap on my 69. Here's some info I posted not long ago on another thread....
Once I changed my rear ratio to 3.55 with the TH350, I was running about 3300 rpm on the highway at around 70 mph. (these numbers might be out a little, but I think they're close)
I like taking my Bird on the highway as well as running around the streets. I'm not racing it, so I didn't have to take those factors into consideration.
The 200R4 offers the best of both worlds, in my opinion. Good (actually better) 1st gear ratio, yet an overdrive ratio for highway driving. ------TH350----200R4 1st---2.52-----2.74 2nd---1.52-----1.57 3rd---1.00-----1.00 OD--------------0.67
From what I understand, the 200R4 wasn't a real strong transmission back in the day, but there are a lot of updates they have developed over the years. If you check out the websites of the guys selling them, they go into detail about the improvements.
Thers's a bunch of guys selling the 200R4 (TCI, Bowtie, Art Carr, etc) that all have the updates done to them.
I bought mine from Gear Star (http://www.gearstar.net/about/). It came complete with trans, torque converter, TV cable, dipstick, synthetic oil). Basically, everything you would need for the installation.
I also picked up a shifter conversion kit from Shift Works (http://www.shiftworks.com/firebird.htm#6869firebird). This kit includes the detent plate, linkage bracket and console selector plate. When you're done, the console still looks original.
I'm now running about 2200 rpms at 65-70 mph. So it's really good on the highway. With the low 1st gear ratio (and 450 ft lbs of torque ) it has lots of get up & go for me.
The TV cable was a little tricky to get set up correctly and I find it's easier to leave the transmission in 3rd around town, shifting it manually into OD when required. Otherwise with the transmission in OD around town, it seems to "search" for the right gear shifting back and forth between 3rd and OD.
Overall, I'm really happy with the results of this installation.
If there's anything else you're wondering about, just let me know. I'd be happy to post whatever I can. Trevor _________________________
i drive my car a lot on the highway.my wife and i love to put the top down and go for long drives on the weekends,many times spending the night somewhere and then driving home the next day.i drive my car at least 4 times a week.thanks for all the info Trevor,greatly appreciated.my rpms on the highway are around 3400 and i don`t want to continue driving any real distances at that rpms.i also like the lower first gear,as i still like to put my foot down ever so often and smell that burning rubber.thanks Allen
Yup, same driveshaft. The trannies are within 1/8" in length, so no driveshaft mods are required and they take the same slip yoke. 200R4 Overall length 27 3/4”, Face to mount distance 26 7/8”, TH350 Overall Length 27 5/8” Face to mount distance 20 3/8”,
The only difference is the cross member mounting (about 6" different). A TH400 cross member needs to be used in place of the TH350 cross member.
I went with Level 2 rated up to 400 hp and 375 ft lbs torque.
Since the purchase and installation, the engine dyno came out at 380 hp and 450 ft lbs of torque. So the torque rating is a little lower than what I'm running. I guees I'll see how it stands up over time.
In hindsight, I'm not sure if I still wouldn't go for the Level 2. The Level 3 is quite a bit more money and my car is primarily a cruiser with the odd squawk off the line.
