During the early ’60s, Pontiac positioned itself as Detroit’s performance leader. Its new Super Duty mills were taking checkered flags on high-speed super speedways and drag strips alike. The program’s plug was pulled in early 1963 when GM issued its infamous anti-racing edict, which forbade Divisions from continued development of packages aimed at competition. Pontiac decided to take what it learned from racing and apply it to street-friendly performance packages.
The GTO concept was created by mating an intermediate-sized body with a large-displacement engine to create a hot street machine. Though faced with corporate restrictions, Pontiac pushed the 389 through for its newest performance vehicle and it made every attempt at extracting as much horsepower as possible from it, and that includes Tri-Power carburetion.
A cold-air-induction package for the Tri-Power GTO, designed by Herb Adams, arrived late in the ’65 model year. Available through dealership parts departments, it consisted of a stamped-steel pan that ducted outside air drawn in from a modified hoodscoop into the carburetors, boosting performance. The pan was revised to accommodate the Tri-Power’s larger-for-’66 center carburetor.
Around January 1966, Pontiac stepped up the Tri-Power 389’s performance with a factory-installed package that included Ram Air. At the heart of the package was the XS-coded 389. It was fitted with a new camshaft with extended duration to improve top-end charge. Valve lift remained at slightly more than 0.400-inch with 1.5:1-ratio rocker arms, however, advertised duration increased from 288/302 (No. 068) to 301/313 (No. 744). A new valvespring package with dampers to positively control valve action was employed.
The “XS” stamping found on this 389 indicates that it was originally equipped with Ram Air
Equipped with Tri-Power induction topped with Ram Air, the XS-code 389 was shipped with its Ram Air pan in the trunk, and the dealership was required to install it and cut open the hoodscoop to make it functional during the preparation process. Even with the enhancements, the XS-coded mill remained rated at 360 hp at 5,200 rpm just like its typical WS-coded Tri-Power counterpart, but performance had certainly improved.
Pontiac’s ’66 engine production log reveals that a total of 190 XS-code 389s were built that model year. We can guess that nearly all were installed into production vehicles, but just how many XS-equipped GTOs were produced has yet to be defined. Estimates between 180 and 185 seem quite reasonable, but we know for certain that no more than 190 were possible. That extreme rarity and the fact that it was Pontiac’s first factory-installed Ram Air package lends greatly to the desirability.
Tom Graves of Wellington, Colorado, owns one such example. “My family has been restoring cars for years,” the 65-year-old retiree tells us. “My brother, Bill, was always into performance cars. I remember as a kid he had a ’69 GTO that ran very well and it made quite an impression on me. He restored a ’66 GTO a few years later and I recall riding along with him. It felt like being in a new ’66 GTO. It was at that point that I got the bug to restore my own car someday.”
In the years that followed, Tom owned and restored other cars. “My brother was living in Richmond, Virginia, at the time and his buddy found another ’66 GTO in the area. Upon obtaining a copy of the vehicle manifest from PHS Automotive Services, he found it was originally equipped with an XS-coded engine, which was still in it. We knew that made the car special, but not really to what extent,” he adds.
When Bill’s buddy decided to peddle the GTO in the early ’90s, Bill bought it with the intentions of restoring it. “My brother moved to Charlotte, North Carolina, and the GTO went with him, but it languished in his backyard. Bill and I had a restoration rivalry going. He’d restore a car; then I’d restore a car. It was my turn, so I decided to restore the GTO he let sit around. One Sunday afternoon in 2004, I talked him into selling me the GTO for $1,000 and some parts for a Buick he was working on.”
Using the manifest, Tom was able to determine the GTO was ordered through Meadow’s Motor Company in Manchester, Georgia. “I planned a trip to Manchester in 2008, and on a whim, was able to locate and speak to the daughter of the business owner. It seems her father passed away a few years before and the family sold the business to a local Chevy dealer. Until about a year before my visit, she had retained the records of every vehicle Meadow’s sold since it opened in 1939, but she tossed the files because they simply took up too much space.”
During that same trip, Tom spoke with Gerry Kirkland, a salesman at Meadow’s Motor Company during the ’60s and ’70s. He explained that even though the dealership was located in a small Southern town, it moved a large volume of Pontiacs, including high-performance versions. It seems that it had a hotline on new performance equipment coming from Pontiac. By marketing to military personnel both stateside and abroad, it would often sell new Pontiacs to returning GIs, sometimes delivering them to other dealerships across the country.
The dash-mounted tach-and-gauge package added $84 to the GTO’s price tag, but it let the d
Pontiac was known for its rich and attractive interiors, and the GTO was no exception. The
The wood-grained four-speed shifter knob - complete with shift pattern and GTO logo - was
Through research Tom began to realize how rare his XS-equipped GTO was. He wasn’t able to determine whether it was delivered new to its first owner in Georgia or somewhere in Virginia, but deduced that it spent most of its life in the Richmond vicinity. “Cars from that area are destined to suffer from premature rusting because of the road salt used during the winter, and this particular GTO suffered greatly from it. Though the odometer showed 61,000 miles, even the frame was rust-pitted,” he reasons.
Tom and his son, Brian, started the restoration project in 2006. The plan was to keep the ultra-rare GTO as original as possible, and they held true to that during the process. They completely disassembled the car, separating the body from the frame. They tended to the frame, painting it with GM chassis black. It was then reassembled using rubber bushings throughout the suspension, new lines for the brake and fuel systems, and reproduction shock absorbers.
Dale and Mike Phillips, the father/son team at Phillips’ Paint & Body in Pierce, Colorado, placed the body on a rotisserie and mended the ailing panels. The GTO was media-blasted to expose the bare metal. The original doors and quarters were salvaged using patch panels where necessary. The fenders, however, had to be replaced using reproductions sourced from Ames Performance.
The body was prepped using four coats of Dupont primer. Six total coats of Dupont Blue Charcoal base were then applied. That was followed by six total coats of Dupont clear, and sanding with papers ranging from 300- to 600-grit was performed between each. The top coat was wet-sanded using 1,000-grit paper and polished to a glass-like finish using Dupont products.
The XS-code 389 was very complete and retained most of its original components. It was sent to Doug’s Machine & Custom Grinding in Fort Collins, Colorado, where it was determined that one cylinder needed sleeving because of wall scarring left behind while removing a frozen piston. The rest would clean up with a 0.030-inch overbore, which took the total to 4.09 inches. The main- and rod-bearing journals on the original 3.75-inch ArmaSteel crankshaft required only polishing. Total displacement equates to 394 ci.
The block was filled with reconditioned cast-rods and cast-aluminum stock-replacement pistons. A 60-psi Melling oil pump disperses the lubricant that resides in the stock oil pan. The original distributor fitted with a Pertronix electronic module in place of the contact-points set routes the spark generated by the stock-replacement coil to the cylinders through reproduction spark-plug wires.
The mating surfaces of the 389’s original No. 093 cylinder heads were machined just enough to true up all surfaces. A standard valve job was performed, and new stock-replacement, 1.92/1.66-inch valves were installed, along with springs matched to the reproduction 744-spec camshaft. The actual compression ratio calculates to nearly 10.5:1, and according to Tom, it runs suitably on premium-grade pump fuel, though he admits it isn’t driven regularly or hard.