Adapting TH 350 or 700r4 tranny to Chevy 250 inline 6

700r4 is overkill for the little 6, if you need od go with a 2004r which is almost the same size as a th350

 

@Francisco Serrano , start a new post.

 

Hello all, by chance does anyone have videos or how to info from start to finish, on how to install a th350 to a 250 inline 6?
I have a 250 currently in my 63 suburban with a 3 speed but I want to swap that 3 speed with the TH350 I also have. Any info will be appreciated.

 

It should be a direct bolt in exchange. The T350 will run with the kick down cable, it just won't kick down and will short shift at full throttle. The later 250's came with the right linkage brackets to hook the cables to. You will need some sort of shifter, floor mount or a replacement steering column for an automatic.

 

Some of us learned how to do this without watching videos. How could that be?

That truck has a crossmember under the bellhousing, which supports the transmission. You'll need to get a different crossmember to go under the back of the transmission. You'll also find there's a crossmember back there for the parking brake, that's kind of in the way, and won't work to hold the transmission. So you'll have to deal with that. Then you might want to cut out the original bellhousing crossmember, because it's in the way of installing the transmission, unless you also pull out the engine.

You'll need to get the driveshaft shortened, and get the correct yoke with splines that fit the transmission.

You need a shifter. And a transmission cooler. And a vacuum line to the modulator. And the kickdown cable and brackets to adapt it to the throttle linkage/carb. The speedometer cable might be long enough, or it might not.

Along with finding the correct flexplate, and shorter bolts to attach it to the flywheel, and the correct length bolts to attach it to the torque converter. You will then need to mount the starter to the engine block, since you're removing the bellhousing that the original mounted to. The starter requires the correct special knurled shank bolts. Oh...there are two different sizes of flex plate, and two different types of starters to mate with them.

There are more things I forgot to list, but this should get you started on your research.

Make a nice complete video, to help out all the other guys that also want to do this.

Also, note the date of this thread, it's over 20 years old. This is one of the oldest thread resurrections I've seen! congrats. You'll probably get a few replies from guys trying to answer the original question from 22 years ago.