427-Powered Arntz Industries Cobra Replica Project

Description

Developed by engineer Steve Arntz, the Arntz Industries Cobra replica emerged in the 1970s as one of the earliest and most advanced recreations of the legendary Shelby Cobra. Production ran from apprxoimately 1974 through 1980, utilizing a steel ladder frame, repositioned engine for improved balance, and a multi‑layer fiberglass body. Known for exceptional rigidity and safety, Arntz cars incorporated steel‑reinforced door structures and featured advanced suspension options. Fewer than 100 Arntz cars are believed to have been built before the company closed, after which Ron Butler acquired the molds and continued development.     Said to have been constructed in 1978, this Arntz Industries Cobra has been re-powered under current ownership with a 427ci Ford V8 engine paired with a C6 three-speed automatic transmission. It's finished in metallic red over a black interior, and features 15-inch Halibrand-style wheels. Additional work following the seller's 2025 acquisition is said to have included replacement of the brake calipers and master cylinder, installation of an aluminum radiator, and fitment of Cooper Cobra Radial G/T tires.    This 1978 constructed Arntz Industries Cobra is now offered as a project with build documentation and a clean Oklahoma title in the seller’s name.

Highlights

• Designed by Steve Arntz, an engineer and early pioneer of Cobra replicas

• Production numbers estimated to be under 100 units produced

• Finished in metallic red paint with black upholstery

• Custom 5-lug “Halibrand”-style wheels with knock-off covers

• Powered by a Ford 427ci V8 engine

• C6 three-speed automatic transmission

Factory Equipment

• Steel ladder frame construction

• MG MGB-based front suspension

• Jaguar XKE-sourced independent rear suspension

• Rack-and-pinion steering

• Four-wheel disc brakes

• Fiberglass body wit 1967 Cobra styling elements

Modifications

• Transmission cooler

• Aluminum radiator

• 2,500 RPM stall converter

• Replacement seats

Servicing & Documentation

• Services within the last 6 months are said to have included the following:

  • Installed a Ford 427ci V8 engine

  • Installed an aluminum radiator with electric cooling fan

  • Replaced the temperature gauge and sending unit

  • Replaced the master cylinder

  • Replaced the front and rear brake calipers

  • Replaced the brake pads

  • Installed Cooper Cobra Radial G/T tires

Known Imperfections

• The seller has included photos of cosmetic imperfections

• Missing the soft top frame mechanism and side curtains

• The seller states that the brakes require service

Ownership History

This Arntz Cobra replica was purchased by the seller from the original owner’s family in 2025. Previous ownership history has been provided in the photo gallery.

From the seller, “I purchased the car from a friend's widow with the intentions of restoring it and going vintage racing. The 427 cross-bolt motor is fresh with no miles, all new internal parts, and camshaft specs in the photo gallery. I replaced the master cylinder, calipers, pads, and front flex lines, but I have not been able to get a good brake pedal. I just had surgery and won't be able to finish the restoration, so I'm selling it to someone who can finish it and enjoy it. The miles that are on it were put on while it had a 427 SOHC motor, and the motor that is in the car was sitting next to the car and was never run in the car. John Brown, a well-known Shelby restorer, built the motor, installed it, and got it running. The car will need very little to finish unless the new owner would want to repaint it.”

Included Items

• Build documents

• Spare seats

• Soft top

Additional Information

The clean Oklahoma title lists this vehicle as a “1978 SHBO Replica.”

This Arntz Industries Cobra Replica Project was offered on Hagerty Marketplace in March 2026. You can view the previous listing here. The winning bidder failed to complete the purchase. This was of no fault to the seller of the vehicle.