Transmission Conversion

[JrCarr]

Hello everyone, I currently have a 1970 Short Bed Step Side. It has a 350 engine with a 350 transmission. I am thinking about converting the transmission over to a 700r4 and wanted to do some research on this. I would like to hear pros and cons if possible. If you can share your information, your experience with the conversion, what to look for and what to say away from. Also, if there is anyone here in the San Gabriel area of Los Angeles who knows of a local shop they can recommend it will be greatly appreciated.

[Grumpy old man]

There are no cons you will be very happy with the swap

[OrangeCrush1970]

I made the switch 2 years ago. I also swapped out my 3.08 for a 3.73 rear end and I like the final drive... You should defiantly look into a lock up converter from TCI, you cant go wrong. You may also want to research how much stall, if any, you will need for the cam you are running. If you are stock or somewhere around an RV cam you should not need anything more than stock. You can do this on a pretty tight budget if you are able to do the install yourself.

Good luck!

[GASoline71]

Make sure the TV cable is set up properly. If not you can destroy a 700R4 pretty darn quick.

Gary

[derotoreut]

Have you considered a 2004R at all? From what I understand, you would not need to change the length of your driveshaft and pretty straight-forward swap. Some will argue the strength of a 2004R compared to a 700R4, but if it's properly built I don't believe it would be a problem. Either way… I'm watching this thread. Chime on!

[hyarbour]

Didn't have to mess with drive shaft length on the long bed I used to have. Just moved the cross member to the TH400 holes and the drive shaft bolted right up. Don't know if the short beds are that easy or not

[Z10]

I'm in the middle of the same install now. Check out my build thread for more.

[Fitz]

Originally Posted by JrCarr

Hello everyone, I currently have a 1970 Short Bed Step Side. It has a 350 engine with a 350 transmission. I am thinking about converting the transmission over to a 700r4 and wanted to do some research on this. I would like to hear pros and cons if possible. If you can share your information, your experience with the conversion, what to look for and what to say away from. Also, if there is anyone here in the San Gabriel area of Los Angeles who knows of a local shop they can recommend it will be greatly appreciated.

The 200R4 is the OD transmission that went into all of the 454 powered trucks in the 80's. It is stronger than the first years of the 700R but since it was designed specifically for trucks it has a very tall first gear. The 700R4 has a higher ratio so wheelspin on starts is lessened but the 200R can pull stumps in first which is not wise with the 700. The good thing about the 200R4, is it is the exact same length and installs just like the TH350 you have so you won't be shortening the driveshaft or replacing trans cooler lines.
With a 350 engine (which I assume is stock) you probably don't develop enough torque to make the 700 behave any differently than the 200 but if you start hot rodding that motor be sure to buy a later version of the 700 from a knowledgeable trans builder. You will like either one and the difference at 70 mph IS noticeable between either one and the TH350.

For the 200R4 I would use Art Carr in Huntington Beach.
California Performance Transmission
5502 Engineer Dr
Huntington Beach, CA
92649
(714) 901-3777
for the 700R you are on your own. I have not used that box.

Good Luck with your truck!

[WIDESIDE72]

Originally Posted by Fitz

The 200R4 is the OD transmission that went into all of the 454 powered trucks in the 80's. It is stronger than the first years of the 700R but since it was designed specifically for trucks it has a very tall first gear. The 700R4 has a higher ratio so wheelspin on starts is lessened but the 200R can pull stumps in first which is not wise with the 700. The good thing about the 200R4, is it is the exact same length and installs just like the TH350 you have so you won't be shortening the driveshaft or replacing trans cooler lines.
With a 350 engine (which I assume is stock) you probably don't develop enough torque to make the 700 behave any differently than the 200 but if you start hot rodding that motor be sure to buy a later version of the 700 from a knowledgeable trans builder. You will like either one and the difference at 70 mph IS noticeable between either one and the TH350.

For the 200R4 I would use Art Carr in Huntington Beach.
California Performance Transmission
5502 Engineer Dr
Huntington Beach, CA
92649
(714) 901-3777
for the 700R you are on your own. I have not used that box.

Good Luck with your truck!

I have a 200 4r in a 79 malibu and a 700r4 in my 72. I prerer the 200 4r.

I dont believe the 200 4r was ever installed behind a big block. Nothing bigger than a 307 Olds, actually. In stock form neither of the original od trans had the necessary torque capacity.

[MARKDTN]

Originally Posted by WIDESIDE72

...I dont believe the 200 4r was ever installed behind a big block. Nothing bigger than a 307 Olds, actually....

Correct. The 200R4 was never installed behind any big block or even a 350. Even though the TPI Corvette and the Grand National both are very close in horsepower the 'Vette got the 700R4 and the GN got the 200R4. I think besides the no BOP bellhousing on the 700 a big reason is that the stock Vette will hook up where the turbo Regal will not. When you get the GN to hook up, then you need to build the trans and the cycle continues. The 200R4 can be built to handle the power for sure, but a 700R4 can do it with a lot less mods. The current 4L60E shares some internals with some of the last 700R4 transmissions.

[19GM71]

I swapped an 87 700R4 into my 71. Swapped right in. I didn't have to shorten my drive shaft. I did have to move the cross member back about 3 inches or so and drill new holes. I love it. The lower 1st. and 2nd. gears made a huge difference. I do want to change the 3.08 gears to 3.73 eventually.

[Fitz]

Originally Posted by WIDESIDE72

I have a 200 4r in a 79 malibu and a 700r4 in my 72. I prerer the 200 4r.

I dont believe the 200 4r was ever installed behind a big block. Nothing bigger than a 307 Olds, actually. In stock form neither of the original od trans had the necessary torque capacity.

You are right. The 4L80e and TH400 was used on the 454 trucks.

[67 chevelle]

Originally Posted by Fitz

The 200R4 is the OD transmission that went into all of the 454 powered trucks in the 80's. It is stronger than the first years of the 700R but since it was designed specifically for trucks it has a very tall first gear. The 700R4 has a higher ratio so wheelspin on starts is lessened but the 200R can pull stumps in first which is not wise with the 700. The good thing about the 200R4, is it is the exact same length and installs just like the TH350 you have so you won't be shortening the driveshaft or replacing trans cooler lines.
With a 350 engine (which I assume is stock) you probably don't develop enough torque to make the 700 behave any differently than the 200 but if you start hot rodding that motor be sure to buy a later version of the 700 from a knowledgeable trans builder. You will like either one and the difference at 70 mph IS noticeable between either one and the TH350.

For the 200R4 I would use Art Carr in Huntington Beach.
California Performance Transmission
5502 Engineer Dr
Huntington Beach, CA
92649
(714) 901-3777
for the 700R you are on your own. I have not used that box.

Good Luck with your truck!

I agree , call art car , It seems there are more problems with "built"700r4's than with"built" 2004r's , and the major difference in their operation is the 700r4 has a very low first gear and a fairly large step up in gear ratio going into 2nd

[68K30]

Originally Posted by Fitz

The 200R4 is the OD transmission that went into all of the 454 powered trucks in the 80's. It is stronger than the first years of the 700R but since it was designed specifically for trucks it has a very tall first gear. The 700R4 has a higher ratio so wheelspin on starts is lessened but the 200R can pull stumps in first which is not wise with the 700. The good thing about the 200R4, is it is the exact same length and installs just like the TH350 you have so you won't be shortening the driveshaft or replacing trans cooler lines.
With a 350 engine (which I assume is stock) you probably don't develop enough torque to make the 700 behave any differently than the 200 but if you start hot rodding that motor be sure to buy a later version of the 700 from a knowledgeable trans builder. You will like either one and the difference at 70 mph IS noticeable between either one and the TH350.

For the 200R4 I would use Art Carr in Huntington Beach.
California Performance Transmission
5502 Engineer Dr
Huntington Beach, CA
92649
(714) 901-3777
for the 700R you are on your own. I have not used that box.

Good Luck with your truck!

The TH2004R was so strong Chrysler wanted to use the behind the Cummins turbo diesel in their trucks but unfortunately the trans was out of production and Chrysler had to settle for the Torqueflight.

[WIDESIDE72]

700r4 actually has a lower first gear than the 200 4r. There is a noticeable difference in rpm drop on the first to second shift on the 700r4 as opposed to the 200 4r.

[Longhorn 70]

I have a 700R4 in my Longhorn. It has worked great since 1997. I did have to cut the shaft and do a little bit of electrical to get the lock up to work right.

If you are going to street the truck go 2004R. A lot fewer mods and is great on the street. If you are going to tow or pull, a 700R4 with a big cooler works well but requires drive shaft cut. Measure the transmission you have and compare.

I don't usually race my truck...ahem...but got on it with a new Chevy off the line Saturday. Accross the intersection, he had no chance! After that, it was me that had no chance. 700s get you out of the hole.