Taking a Computerized Chevy Truck Back to the Old School: What’s Up in the Forums

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1989 Chevy Truck

Chevrolet Forum member seeks advice as he tries to turn back the clock on his 1989 Chevy truck.

There’s no denying that modern, computer-controlled, fuel-injected trucks have their advantages. Namely efficiency, power, tuning capability, and lack of necessary maintenance. But on the other hand, you can’t beat the simplicity of an old school carbureted engine that runs without the assistance of sensors and fancy electronics. Thus, you can’t really blame Chevrolet Forum member 97silver for wanting to turn back the clock on his newish Chevy truck.

“I have a 1989 Chevy 1500 pickup that has an OBD I computer. I’m older and not too savvy on the computer end and would like to be able to do the work on it myself. So I would like to put a non-computerized engine and transmission in it.

The engine in it is getting a little worn. What do I have to do to switch the pickup over to non-computerized? What about the gauges and speedometer, etc.? I was told that if I go carb and leave the rest of the computer hooked up, the speedo and gauges should work fine.”

1989 Chevy Truck

Turns out, the OP isn’t the only one working on this sort of change. So is fellow member Exec.Moose.

“Carbed motor with the Turbo 400 transmission has a vacuum line coming off the intake. That allows it to run and drive. Electronics are fun since the dash itself is electronic. I have an aftermarket mechanical gauge. Gauges are going to have to be mechanical from my understanding. HEI Distributor as well.”

He also confirms that the transmission can be retained, with a few modifications.

“You could leave the stock trans in it. Unplug the top connection on the computer, that controls injectors and stuff like that. Bottom plug controls trans, so it’ll be more of a shift module at that point. You can leave the stock fuel pump in, but you’ll have to run a mechanical fuel pressure regulator with a return to the tank from what I understand. With the HEI, you can splice into the wires.”

1989 Chevy Truck

So far, it looks like the OP’s dream of devolving his Chevy truck is moving right along. But he still needs your help! Have you successfully converted a computerized Chevy pickup into a carbureted one? If so, head over here and chime in with your expertise on this subject.

Brett Foote has been covering the automotive industry for over five years and is a longtime contributor to Internet Brands’ Auto Group sites, including Chevrolet Forum, Rennlist, and Ford Truck Enthusiasts, among other popular sites.

He has been an automotive enthusiast since the day he came into this world and rode home from the hospital in a first-gen Mustang, and he's been wrenching on them nearly as long.

In addition to his expertise writing about cars, trucks, motorcycles, and every other type of automobile, Brett had spent several years running parts for local auto dealerships.

You can follow along with his builds and various automotive shenanigans on Instagram: @bfoote.

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