1991 C1500 Sport

[80Alejandro]

I have a a 1991 C1500 i bought which came originally a 5 speed manual according to the vin. My question is what do i need to convert it to a automatic. The vehicle is a rolling chassis. No motor or transmission, but looks like the removed slave cylinder and manual parts. It has a automatic steering column on aswell. Would appreciate your help.

 

[Erik the Awful]

You'll want an automatic cluster with the PRNDL indicator.

What auto are you wanting? A lot of guys will say the only way to go is a 4L80. I'll ask what your purpose is. If it's going to be a drag racing truck or a tow pig, you'll want a 4L80. If you'll just be daily driving it with some infrequent light towing, a 4L60E will be enough.

 

[80Alejandro]

Erik it will be some daily driving just a stock truck. One of my concerns is what do i need to make this work. That year it would have been a 4L60 basically a 700r4. Would i need a different ecm and harness?

 

[Erik the Awful]

Doh! I got that wrong in my head. You're correct, a 700R4, which is what I have in WCJr.

You'll need the TV cable bracket and when you get it together and fire it up you'll need to verify your line pressure before you ever try and drive it.

 

[80Alejandro]

Erik what about the wiring to the transmission because it originally was a manual trans. Don't know what i will need to make it work properly.

 

[Erik the Awful]

The 700R4 does require a wire carrying signal from the ECM for torque converter lockup. You'll also need your neutral safety switch and reverse switch. I don't know how the harnesses match up.

 

[80Alejandro]

Erik that is my only concern with this project . Appreciate the help