Has anyone dealt with them before? I am wanting to install a 2004r transmission in my 1979.

 

Actually, I think the 700R4 will fit directly in where a TH-350 once sat. If I'm not mistaken (and I think correction will be swift, if I am), the 700's length, mounting connections and output yoke are compatible. You may need to make some adjustment to the exhaust system (relatively minor); you will neet to fit a different oil fill tube in the car, I believe; the throttle valve (TV) cable and its proper adjustment may be an issue, as may the shift cable bracket connection and other pan-attached hardware. You also need to know how the lockup clutch is going to be activated/de-activated. Read up on that well, as how you hook it up is important. Getting it to engage is not the issue....getting it to disengage in 'sticky' situations [panic stops, etc.] is where the risks are. A simple ON-OFF switch will work, but that isn't really a good alternative.

But, the change will definitely be worth it if you drive much on the highway...both from a comfort standpoint and from that of 'economy'. It will also 'save' the engine from unnecessary wear & tear when at speed.

 

However it seems a lot more people go with the 200-4R. I think the closer gear ratios in the 200 are more popular.

 

Well, if you are focused on drag racing as the purpose for the tranny change, that might be right. If that's not the case, either unit will serve your purpose (overdrive and lockup) quite well. Pick the one that suits you best. One is just easier to convert than the other.

 

i know that you need to shorten the driveshaft for the 7004r.
i had been looking into Bowtie but Extreme is about 100 miles away.

 

I purchased the 2004r trans from Bow Tie Overdrives. Mine is a 72 and had a 400 turbo in it. The change was easy as it used the same crossmember. I think if the car had a 350 turbo then the 700r4 is the direct change but not positive on that. You can give them a call and they will give you all the information you need even if you didnt purchase it from them. So many people on this site as well as another vette site I belong to have used them so I felt comfortable with them as well. I am from the east coast and the shipping was around 225 bucks. Good luck in your install.
Rodney

 

The 200 is a direct swap. The 700 requires a driveshaft change and welding up a different cross member mounting point.

The 700 can take on higher power, but the gear ratios suck.

Either one unless extensivly modified are very fragile

 

I have an Extreme Automatics 200r4 in my 81. Lonnie is a great guy to deal with and can build a bullet proof 200r4.

 

Just did a 2004R swap from the 350 in my 77'. I was tired of running 3500rpms on the freeway. I would recommend the cross member from BTO. Perfect fit! I have heard the stock cross member would work but if you have a true dual exhaust, the driver side tube passage in the cross member is blocked by the trans pan. The money is worth saving you from the head aches. The drive shaft did not need shortened. You will need to add a 4th gear pressure switch and vacuum switch to control the torque converter lock up function. There are other methods but this one is pretty much hands free for normal driving. TCI has a kit for this and it's a simple DIY install. You will need to replace the detent plate on your shifter for the extra position 123DRND. When buying a 2004R you will want the upgraded corvette servo and upgraded sunshell. I did a couple months of pros and cons research on 2004R vs 700R4 and landed here with no regrets. I'm not a trans expert so I had to read a lot of forums for different opinions. You should do the same.

 

For clarification only:

I am under the impression that the 200-4R will replace the THM-400 easily....and the 700R4 will replace the THM-350 easily. But, if you select the 'other' unit for your particular car, there is significant work to make the swap. I changed out the 400 with the 700R4 and it required a lot of changes (driveshaft, crossmember, exhaust, TV cable, brackets, L/U switch, etc.).

 

Either one will require a T/V swap. The 350 had a detent(down shift) cable and I'm not sure but the 400 had an electronic detent circuit. Neither are used with the 200 or 700. They both use a throttle valve cable which controls fluid pressure for more than just downshift function. Both 700 and 200 will need L/U switch(s) for Torque Converter which were not in 350 or 400. As far a size compatability, the only direct swap dimension is the drive shaft length from 350 to 200 but the cross member mount is almost 7" diff. The 400 to 200 cross member diff is either 1/16, 15/16 or 21/32 depending on the tailshaft. I don't know which came on the vette but I assume it was the shortest.

 

"Phoenix Transmissions" in Weatherford Texas did mine... Asked what kind of driving I did, wheel size, diff ratio ect... Built up a 700R4 for the ZZ383....Did have to shorten the driveshaft.

 

The 200 is the easy sway from a 350 basically as far as fit a direct swap. The 700 swap requires a 3 inch shortening of the driveshaft and modification of the crossmember. So the 2004R from TH350 is the easiest by far.

 

Lonnie builds a great 200-4r I have the stage three. Before I had his I broke FIVE other so called built transmissions. I have had Lonnies 200 for two years and beat the hell out of it and infact just bougth another for my other car.

You can't break his stage 3 200-4r, not with a C3, no way.

 

The 200-4R replaces the TH350 very easily. No driveshaft mods, just unbolt the crossmember mount bracket and the 200-4R bolts to those holes, I "adjusted" the dipstick to fit, factory exhaust fits, I bought a stainles steel braided TV cable that corrects the geometry to work with the carburator of your choice, brackets are available but I made mine ( I had to do something) It practically falls into place.

The lock-up solenoid is already in the transmission, you just have to power it. The 4th gear pressure switch triggers mine, and an adjustable vacuum switch will unlock it when the signal falls below whatever you set it. Bowtie has you covered.

 

if its a stock 79 a 700s low 1st gear would help like mentioned in other post correct tv linage and cable adjustment is important i have a transmission shop in west virginia and most 200/700 shift problems and failures are linked to tv cable not adjusted properly

 

once the tv is properly adjusted, how often has anyone had to readjust it?