1970 K5 blazer tranny

[fortnerm]

I have a 1970 K5 blazer with a 350 in it. I bought it used and almost completely redone. My only problem with it is that it's only a 3 speed. I'm not sure what transmission is currently has. I would like to keep it an automatic, but want an overdrive or 4th gear for the highway. I talked to a few local shops who didn't help much because they said all the transmissions that would work require onboard computers. I find it hard to believe that there's not one out there I could bolt on in its place, but I could be wrong. Does anybody have any reccomendations as to what transmission I should look into getting? and where I should begin my search?
I apologise if this question has been asked a number of times.

 

[bp71k5]

You're best option is a 700r4. It's not completely bolt in, but it's not computer controlled. I'm not sure if the length is the same, if it's any longer than your stock turbo 350, you may have to move the transfer case back a bit.

 

[4X4HIGH]

700R4 is 1 7/8" longer than a TH350.

 

[fortnerm]

does that mean i'll jsut have to move the crossmember back that attaches to the tranny?

 

[4X4HIGH]

You need to figure out what trans and t-case is in your rig before you can go any further. I suspect it is a TH350/205 and if so then you would need the 700R4, teckpak fitzall spacer (7Q-35A), the correct TV cable bracket for your carb, and also your existing TH350/205 adapter to make it work. You will need to relocate the crossmember back to the appropiate position, you will need to shorten the rear driveshaft and lengthen the front and you'll need to correct rear pinion angle once the set-up is installed.

That is all that comes to mind, if i missed something i'm sure someone will chime in.

 

[bp71k5]

You got it covered I think.

 

[imiceman44]

You need to figure out what trans and t-case is in your rig before you can go any further. I suspect it is a TH350/205 and if so then you would need the 700R4, teckpak fitzall spacer (7Q-35A), the correct TV cable bracket for your carb, and also your existing TH350/205 adapter to make it work. You will need to relocate the crossmember back to the appropiate position, you will need to shorten the rear driveshaft and lengthen the front and you'll need to correct rear pinion angle once the set-up is installed.

That is all that comes to mind, if i missed something i'm sure someone will chime in.

The only thing you left out is teh lock up converter, there a few solutions for that manual or auto, but it's all feasable.

 

[Thunder]

It would be best to avoid your local shops if they told you you need a computer. They dont know what they are doing.
Talk to these guys: http://www.bowtieoverdrives.com/index.shtml
They have most everything to help you put a 700r4 4 speed OD into an older vehicle and make it work right. I can recomend their trannys they do good work.

 

[4X4HIGH]

The only thing you left out is teh lock up converter, there a few solutions for that manual or auto, but it's all feasable.

Oops, figures i missed probably the 2nd most important part.