First, let me explain that the main reason I used a 700R4 transmission is because the car came with a practically new one when I purchased it. I very much like the 700R4, but would highly suggest using a newer electronic transmission with your swap. Whether it be the widely despised 4L60E, the more robust and reliable 4L80E or better. These electronic transmissions will integrate easily into your ECM controlled system.
On a side note, you most likely already know that the 700R4 was renamed to 4L60 in 1990. They are the same transmission. In 1992, the throttle valve was replaced with electronics in the 4L60E. The 700R4, 4L60 and 4L60E are rated for and entirely capable of handling the horsepower and torque of a stock LS-based truck motor with stock rear-end gearing and street tires. As long as you are not abusive to it, it should remain a functioning one-piece unit.
700R4 transmissions require a working, correctly adjusted Throttle Valve Cable, otherwise known as a TV cable. Often incorrectly called a Kick-down or Detent cable, it is in fact different than those. The TV cable controls the valve pressure and tells the 700R4 when to shift, not just to kick-down into passing gear. An incorrectly adjusted TV cable can cause the transmission to overheat and fail prematurely… like when you are driving.. far from home… on a rainy day…
When attaching a TV cable to a carburetor, simply purchase and install the correct bracket and corrector plate made for your specific model carburetor. These can be purchased at your favorite local or online auto parts store.
When attaching a 700R4 TV cable to a throttle body you must take care in getting the connecting mechanism to the correct geometry and travel. You can purchase a TV cable kit from Bowtie Overdrives for LS1 setups. The bracket may require slight modification or fabrication to work on a truck LS intake/throttle body. Or you can, with lots of careful work, manufacture your own as I did.
I used the following information to create the bracket and connector for my throttle body. Therefore basically emulating the carburetor setup as seen above.
I used a donor throttle body valve for the connecting arm. I removed it and did some cutting on it for clearance to “lock” behind the throttle cable connector on the throttle valve as to help with placement. Otherwise it would have kept falling off as I test fitted and welded it.
I was not confident that welding the arm onto the throttle valve would not damage the internal bushings, so I opted for JB Weld. After careful measuring I marked the center pivot of valve, and the desired angle for the new arm. This photo was actually my first attempt. I had to remove and re-place it due to having made a fractional error in placement.
The bracket was cut and welded using the OEM L59 throttle cable bracket and the TV bracket from Holley that come from the engine I pulled from the wagon. This photo was also my first attempt as I had made another error on it also, according to the above dimensioned drawings. A simple cut and short movement put it all into it’s correct place.
Here’s the final version of connector and bracket painted, installed and everything in it’s place. I took it to the transmission shop and they approved the setup and adjustment.
There are many videos on YouTube to help you understand the importance of the cable adjustment and how to adjust correctly, but this one seemed to help me understand it more than most.