700r4 swap

[Pilot-209]

I have a 700r4 out of my dad's 1989 chevy pickup. I would like to put it in my '72. I believe it was controlled by the computer and I am wondering what it takes to make the swap. I currently have a turbo 350 and a small block 350ci engine. Any help will be appreciated. Thanks

[Tx Firefighter]

An 89 model trans will not be computer controlled. They started that a few years later.

Depending on which TH350 you have currently, you will have to change your driveshaft length. There are three different lengths of TH350 transmissions so you will have to measure your trans and compare it's length to the 700R4.

You can reuse the existing cooler lines, shift linkage, mount, and crossmember. The crossmember will however be moved rearward from where it sits now so once you get it all installed you will have to drill new holes in the frame for the new crossmember location.

The most important thing to note is that you will need to set up the cable to the carburetor on your truck. It has to be set up with specific geometry to assure the 700R4 enjoys a long life. The 700 is quite sensitive to thus issue. I make my own brackets for it, but most guys seem to buy the bowtieoverdrives kit for it.

[cdowns]

you'll also need an electronic kit to lock up your converter if you want to use that feature// the kits available from painless wiring or bowtie overdrives plus others have it too

[Indyuke]

It's a pretty simple swap... and firefighter and cdowns have pretty much said it all. I did the same exact thing you're doing... put a 89 700r4 into my 70 c10 that used to have a turbo 350 trans. I've got about 30,000 miles on it now.

The most costly part of the entire swap for me was having the driveline shortened and rebalanced for about $200. I also had them put in a new carrier bearing. The throttle valve cable setup for my carb was $109 bucks at bowtieoverdrives.com. Other than that it was a bolt in affair with only having to move the crossmember back a few inches and move the shift bracket back about 1 inch.

Setting up the TV (throttle valve) cable was easy with bowtie's kit.

I did my own wiring for the torque lockup though, as it only amounts to about six feet of wiring and a few components.

[Pilot-209]

Thank-you! I thought I would have to purchase an expensive computerized controller. Now I just have to see if I can make my own bracket or get on from bowtie. I will also have to do some research to know how to get the TV cable adjusted correctly. I appreciate your quick and informative responses. This is definitely the best forum for these trucks. You guys are great!!

[profe56]

I´m doing exactly the same swap and I´m finding funny, today I was starting to install the flywheel but it doesn´t bolt because is a newer type (87s), tommorrow I¨ll buy the correct flywhhel.
Is the lock converter very important and necessary or can I use the transsmission without the lock?
are there benefits and advantage install it?

[beebster]

thanks to txfirefighter advice i purchased the th350 that is the same length as the 700r
I had a choice between 3 different t350's, i chose the 9" tailshaft and installed it and had a 1 piece driveshaft made. Now, when i'm ready to puchase the 700r it'll just be a matter of sliding,drilling the crossmember back, getting the bowtie lockup kit and i'm good to go. I'm seriously thinkin about the LS1 swap in the future
great advice on this site!

[Newtz67]

Now I know all your secrets, pilot! haha

[Indyuke]

Profe, You can use the trans without the torque lockup, but the disadvantages outweigh the advantages. The lockup will take the trans out of "fluid drive" mode and drop your rpms about 200, so rather than spinning 2500rpm on the highway, you're spinning at 2300. Nice for fuel economy and noise reduction.

I think the trans also runs hotter without the torque lockup.

[VetteVet]

Go here for more info on the TV system.
http://www.tvmadeez.com/article/index.php