1966 GTO Restoration Guide

by Rob Wagner

Restoring a 1966 Pontiac GTO is an arduous task that requires extensive knowledge about the car. GTOs present special challenges because they are performance cars immensely popular among enthusiasts willing to up to $25,000 for a pristine version. Enthusiasts often modified GTOS or cannibalized parts from others for repair. This makes restoration to original factory specifications an expensive and difficult project.

Restoration Levels

Restoration of a GTO means only one thing: restoring the car to the condition on the day it left the factory assembly line. Every nut, bolt and odd widget should originate from the factory. Budget constraints, however, often make full restoration impractical. If you can live with without the small details of a full frame-off restoration, consider focusing on what is important to you. This might be the 389-cubic-inch V-8 engine restored to factory specs or the body returned to its original color with factory badges, chrome trim and correct factory wheels.


The most difficult and important aspect of auto restoration is research. Purchase 1966 Pontiac GTO/Tempest/LeMans shop and parts manuals. These manuals provide systematic instructions for disassembly and assembly of parts and list every part. Purchase an owner's manual that sits in the glovebox. It has a wealth of information on the operation of the car. Purchase or download exterior, interior and engine compartment photos of original 1966 GTOs. Purchase or download interior and body color charts to match paint and fabric. Serious restorers will attend car shows and photograph factory original GTOs and pepper owners with questions about their restorations.

Your Car

Research your GTO by writing down the vehicle identification number and matching it against online Pontiac VIN charts. The VIN tells you what engine and transmission belongs in the car. It identifies the car as a coupe, four-door sedan or convertible. The 1966 GTO featured a 389-cubic-inch V-8. If your car has a 421-cubic-inch V-8, it's likely from a Pontiac Catalina. You can keep the 421, but your GTO is not a restoration piece. Dump the 421 and find a 389 with triple two-barrel carburetors that fits your GTO. A new 389 is not original to the car, but close.

Work Environment

Cleanliness and preparation are paramount to a successful restoration. Invest in the right equipment. A 100-piece tool set in a rolling toolbox is the minimum requirement. Purchase an engine hoist, hydraulic jack and four floor stands. Have a means to dispose of oil and cleaning liquid waste. Keep your work area spotless at all times. Make sure you have a friend available to help with the heavy lifting. If you are performing a frame-off restoration, purchase a hoist that allows you to lift the body from the frame. Label each part after removal and bag it.

Devil in the Details

A restored car is not a perfect car. As a factory car, it may feature overspray under the wheel wells. Consider these imperfections as interesting touches. Each make and model car rides at a specific height, so leave the springs alone unless damaged. Your 1966 GTO's engine features light metallic blue paint, not the 1965 GTO's solid light blue. Fellow GTO owners will spot such mistakes. If your GTO left the factory in October 1965, make sure your parts catalog wasn't published at a later date because it will list parts not specific to your model.

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