slowup

my dad has a 69 big block 427. Its a full roller engine and it has the original turbo 400. The problem is is that he has a 4:56 rear end and the car is now a RPM monster. I told him that a lot of u guys on here have auot overdrives and he got very interested. And no he wont convert it to a 5 spd or 6spd OD cuz he said that hes "sihfted enouigh gears in his lifetime", lol. But i forgot what the trannies were called. Was it somethin like 700r4 or w/e? And if so will it bolt in directly or will we need to make some mods to it?
thx!

markdtn

700R4 is the transmission (or 200R4 which I don't prefer, but there are differences of opinion). A stouter transmission is a 4L80E, which is basically a TH400 with overdrive. The problem with a 4L80E is that it requires a computer to run it and it may require tunnel mods to make it fit in a C3. I have heard you can use a controller from a mid-90s diesel pickup, but don't know that for sure. Either will bolt right to your block. Both will require shortening the drivesahft and a different transmission crossmember.

See www.bowtieoverdrives.com
do a search on 700r4 swap

audiec

I think I will go this route in the future...

http://www.gearvendors.com/index.html

Audie

marshrat99

I did the TH350 to Bowtie 2004R swap this past winter on my 79 and haven't regretted it. I've got a 355 rear and now tack @ 2K RPM at 70MPH. On their website, Bowtie has a calculator so you can see where your RPM is going to end up with their tranny and your rear. The conversion was straight forward with no issues and didn't have to shorten the drive shaft. Although I did purchase the BTO cross member, I've heard on the Forum that the stock 79 cross member will work. The first 3 gears of the 2004R are identical to the TH350 so I didn't loose anything, just gained a great 4th gear for crusing. Mileage increased from 15MPG to 20+MPG.

redwingvette

I have the BTO 200-4R and love it. I also run a 3.55 rear gear and mine came with the TH400. overdrive auto install

jackson

If Dad's content w/sitting on the fence ... let him wait a bit longer ... until the NEW SIX speed autos begin to appear in the yards ... 6L65 & 6L80.

GrandSportC3

I'd recommend the TH200R4! It's a bolt on swap and even uses the same driveshaft length!! Same mounting location etc..
It can be built to hold up to 800+ Horsepower. I have about 100 drag strip passes on my TH200R4 (with a 600+ HP engine) and it still works perfect

MIKER

I like my 700R4. It's well built and has a really crisp shift. However,GrandSportC3's post makes your decision easy. Easy swap and durability all in one package.
A 2004R built up just like his will last your Dad a long time.

If you purchase a 2004R or 700R4 that is poorly built or fail to set it up correctly, either one can have a VERY short life.

Keep us updated on your decision.

MIKER

Here is the speed vs. RPM range for a 2004R with 4.11 gears.


Here is the speed vs. RPM range for a 700R4 with 4.11 gears.

worship79

Very interesting! What else does one need besides the tranny itself? Kabels, brackets, switches...? How does a 200R4 cost these days anyway?

fl_rider

A local Transmission shop quoted me $1300.00 with a torque converter.

www.bowtieoverdrives.com has all the goodies.

kaiserbud

Miker - nice info on eth rpms/speeds.
Jackson - I did not know about the 6 speeds - now that sounds interesting - but can they hold up to the hp?

I searched real quick and found that there may even be a 6L90E model. But there is some discrepancy as to when they will actually be in production

GrandSportC3

The street version (also rated 800 HP) shold go for below $2500 including converter and all necessary brackets, filler tube etc..!! I paid $3000 + shipping for mine

The kit comes with:

1) Transmission
2) Converter (built to your specs)
3) tv-cable
4) tv-cable bracket (for Holley carbs)
5) filler tube


http://www.cpttransmission.com
That's all you'll need...

This unit is a lot stronger than most other TH200R4's available. With stock power, the BTO TH200R4 should be strong enough..

slowup

thanks for all the great info guys. I told my dad what u guys said and hes still contemplating about it. He still doesnt know which one to get at the moment so i'll try to keep everyone informed.
thx again!