1946 Chevy Truck / 2002 Prius Unibody Chassis Swap ~ Wait… WHAT?!

 

Joe Winter of Hoopie’s Hot Rods in Ohio originally planned to mount a classic 1946 Chevrolet truck body on top of an ’02 Prius unibody/chassis.

It became clear quickly that that approach was not going to fly. After pondering possible solutions, it was decided to cut the front clip off the truck frame and the back half of the Prius unibody, then make them one by essentially stacking the two sections and weld the truck frame to the Prius unibody using steel to make up the gap.

Joe Winter of Hoopie’s Hot Rods
Joe Winter of Hoopie’s Hot Rods

After solving a several additional challenges, the classic truck is now driving around town and is likely getting better gas mileage than any other ’46 Chevrolet truck in history. On the outside, few even notice that the truck is now powered by a 1.5 Liter 1NZ-FXE inline-four engine mated to a CVT transmission.

The Builder, Joe Winter, Explains the Chassis Swap Project…

Project Build Photos

1946 Chevrolet Truck - 2002 Prius Unibody Chassis Swap
1946 Chevrolet Truck - 2002 Prius Unibody Chassis Swap
1946 Chevrolet Truck - 2002 Prius Unibody Chassis Swap

Cutting. Cutting. And more cutting…

1946 Chevrolet Truck - 2002 Prius Unibody Chassis Swap

Test fit. I ran the tape measure a lot that day. At this point I was thinking of running the complete Prius drive train and putting a tiny bed on it…

1946 Chevrolet Truck - 2002 Prius Unibody Chassis Swap
1946 Chevrolet Truck - 2002 Prius Unibody Chassis Swap

Change of Plans

I didn’t like the way the truck was coming together. I sat in the shop and stared at the project thinking it was going to look stupid. Something needed to change.

Then, with about an hour before I had to leave an idea hit me. Why not do a sub-frame? Years ago I put a Firebird sub-frame on a ’56 Chevy. It gave me smoother suspension, disk brakes, and power steering.

I measured the frame rails on the truck frame and on the Prius and they were almost exactly the same. So I grab the Sawzall and cut the front clip off the truck frame and rolled the rear section inside.

I cut the Prius just in front of the fuel tank. Using some 4 x 4s as spacers, I laid the truck frame on top of the Prius floor and ratchet strapped them together, and set the cab on top. I loved it…

1946 Chevrolet Truck - 2002 Prius Unibody Chassis Swap

I finally decided to weld the two together. This was a bit stressful. I measured, nudged, measured, tugged, measured until I thought/hoped it was true. Then said a prayer and started tacking it together. I continued measuring after every weld…

1946 Chevrolet Truck - 2002 Prius Unibody Chassis Swap
1946 Chevrolet Truck - 2002 Prius Unibody Chassis Swap
1946 Chevrolet Truck - 2002 Prius Unibody Chassis Swap
1946 Chevrolet Truck - 2002 Prius Unibody Chassis Swap
1946 Chevrolet Truck - 2002 Prius Unibody Chassis Swap
1946 Chevrolet Truck - 2002 Prius Unibody Chassis Swap
1946 Chevrolet Truck - 2002 Prius Unibody Chassis Swap
1946 Chevrolet Truck - 2002 Prius Unibody Chassis Swap
1946 Chevrolet Truck - 2002 Prius Unibody Chassis Swap
1946 Chevrolet Truck - 2002 Prius Unibody Chassis Swap

Search Project Cars and Donor Cars for Sale

I was able to lengthen the brake pedal and weld the original foot pad to the extension. It’s slightly off to the right but I don’t believe it will put it in a bind. I may need to put a slider on it to keep it from twisting to the left. More testing to see if it’s safe.

1946 Chevrolet Truck - 2002 Prius Unibody Chassis Swap

I was able to use the Prius shifter — I flipped it over on top of the ’46 column and the PRND stick lays nicely bellow the dash. This keeps it out of site and I will attempt to give it the appearance of a hand brake…

As far as steering was concerned, I wanted to use the original ’46 column and wheel. To my surprise the truck steering rod lined up with the Prius steering box. I did have to drill a hole trough the firewall on the cab to get the angle correct.

I was able to cut one of the steering knuckles and welded it to the truck steering shaft. It slid right into place and the electric steering worked like a dream.

1946 Chevrolet Truck - 2002 Prius Unibody Chassis Swap
1946 Chevrolet Truck - 2002 Prius Unibody Chassis Swap

I had to drill a hole for the shift cable. Because I flipped he shifter mount it lined up perfectly. You can also see the hole I drilled for the column…

1946 Chevrolet Truck - 2002 Prius Unibody Chassis Swap

A 1946 Chevy truck has the gas tank under the seat. This is plenty of room for the HV Battery. I’ll need to get creative on how to keep it cool, but there’s plenty of room between the truck floor and the Prius floor. This area should accommodate a fan and some duct work…

1946 Chevrolet Truck - 2002 Prius Unibody Chassis Swap

It Finally Runs

Up to this point I had never heard a Prius start and run. I was somewhat of a anti-Hybrid person. It was ignorance. I never paid attention to them, therefore had no memory of what they sounded like. My first thought was, it sounds like an electric generator.

Weird, I’m used to V8s — loud, obnoxious, gas guzzlers. This was a little hum. Then as I celebrated this mile marker — it happened… it died.

I thought, oh crap, what’s wrong? Looking to Jeff, he informed me that the batteries charged and it turned itself off. Obviously I was new to the Hybrid world. Now I needed to hook up all the controls…

1946 Chevrolet Truck - 2002 Prius Unibody Chassis Swap

The Prius tank fit nicely between the frame rails…

1946 Chevrolet Truck - 2002 Prius Unibody Chassis Swap

Mounted cab today and created firewall to firewall brace. The ’46 metal is incredibly thick. I was able to use original holes the mount a piece of angle iron to the truck. Then I welded the bracing to the Prius firewall. The lower brace attaches to a solid bracket that Toyota used as a structural support.

The upper brace attached to solid sheet metal near the top of the firewall. I believe this will be adequate support…

1946 Chevrolet Truck - 2002 Prius Unibody Chassis Swap
1946 Chevrolet Truck - 2002 Prius Unibody Chassis Swap
1946 Chevrolet Truck - 2002 Prius Unibody Chassis Swap

Here’s a shot of the engine compartment. You can see I will be able to use the Prius heater and A/C unit. It fits nicely between the firewalls…

1946 Chevrolet Truck - 2002 Prius Unibody Chassis Swap

First gen Prius have a 4 x 100 bolt pattern. Also the track width is much narrower. So I searched for and found a 4 x 100 to 5 x 4.5 adapter that was 2″ thick.

Now I can run 5 lug steel wheels and maintain the proper track for the truck body…

1946 Chevrolet Truck - 2002 Prius Unibody Chassis Swap
1946 Chevrolet Truck - 2002 Prius Unibody Chassis Swap
1946 Chevrolet Truck - 2002 Prius Unibody Chassis Swap
1946 Chevrolet Truck - 2002 Prius Unibody Chassis Swap
1946 Chevrolet Truck - 2002 Prius Unibody Chassis Swap

The 1946 Chevrolet Prius Hybrid’s First Show

Source: EcoModder (build photos) and Hoopie’s Hot Rods (videos)