1966 GT350 # 2031 History - Original Paxton Car
Shelby GT 350 #SFM6S2031 is one of only 11 factory built,
Paxton Supercharged, 1966 Shelby GT350s. When production of the Paxton
supercharged cars ceased at the end of the 1967 model year, the Shelby American
World Registry estimates only 50 to 100 total Paxton supercharged GT350s were
ever constructed by the factory. More information on the Paxton GT350s is set
forth below in an excerpt from the 1997, Shelby American World Registry, page
In early 1965, Paxton Products’ Joe Granatelli approached Carroll Shelby with
the idea of providing a supercharger kit Shelby could install on GT350s as an
option. Shelby was skeptical but lent Granatelli a ’65 GT350 (5S425) as a test
vehicle. After the installation was complete Granatelli met Shelby in the back
of Shelby’s airport facility with the car. Still skeptical, Shelby brought a 289
Cobra with him to compare the supercharged GT350 against. When Granatelli, in
the GT350, walked away from Shelby in the Cobra, Shelby was convinced, and
promptly gave him an order for 500 Paxton supercharger kits.
Paxton did not install any of the kits, themselves, on GT350 production cars.
That was done at Shelby American. Paxton only worked on prototype cars in
advance of the new model year. The original carburetor supplied on
Paxton-equipped GT350s was the Autolite 4100 4V with mechanical choke. It was
rated at 460 CFM and, according to Paxton, this was the best carburetor for this
application. It fit inside their pressure box without problems and required only
one jet change.
The original Shelby carburetor pressure boxes had the word “Cobra” cast into the
front of the top half. Towards the end of Paxton production the boxes were
changed to read “Shelby” because Shelby had sold the “Cobra” name to Ford and
was not allowed to use that name on aftermarket items. Fuel pumps supplied with
the kits were Carter High-Volume units, specially ordered by Paxton and
assembled with thicker diaphragms and heavier springs. The pump housing was
modified by Paxton to supply the pump with supercharger boost.
Early supercharger compressors were painted black (later ones were painted Ford
Blue and around 1968 they were painted white). When they were shipped from
Paxton they carried red and black Paxton emblems which were affixed to the top
portion of the compressor. Once the got to Shelby American, the Paxton emblems
were removed and replaced with red, white and blue “CS Shelby American” emblems.
All Paxton compressors were individually serial numbered. Early Cobra blowers
contained the prefix “C” in their serial numbers. Later in production (around
1967) the “C” was replaced with an “S”. Paxton units without either a “C” or an
“S” at the beginning of their serial numbers are standard aftermarket blowers
from Paxton and not Shelby American. The serial number was a 9-digit number; the
first four digits the unit’s consecutive production number and the last 5 digits
the date of manufacture (01116 was January 11, 1966). A date was necessary
because each supercharger carried only a 90-day warranty.
In the summer of 1965, as the first 1966 GT350 models were being assembled,
Shelby American pulled one car out of the production line and painted it Ivy
Green. This car, 6S051, was the first GT350 that was not white. It also became
the 1965 Paxton Prototype. It was given a Paxton supercharger and white rocker
panel stripes which carried the designation “GT 350 S.” At that time, Shelby
American was planning on offering the Paxton-equipped cars as separate models.
However, it was later decided to offer the supercharger as an option. The cost
was $670 and included a pair of Paxton gauges (manifold pressure and vacuum)
mounted in a chrome bezel under the center of the dashboard. Shelby American
claimed a 46% horsepower increase with the Paxton supercharger. Various road
tests of cars in 1966 put the peak horsepower between 390 and 400.
The only other modification required was an air-inlet hole cut into the radiator
support bulkhead, on the driver’s side. The compressor was mounted behind the
support and its inlet hole was mated to the bulkhead hole, which was covered by
a mesh screen.
Shelby American factory invoices show that a total of 11 1966 GT350s were
shipped with Paxton superchargers. This number included 6S051, which, after use
as an engineering prototype, was eventually sold as a used car. The Paxton
option was continued throughout the 1967 model year, but was only available on
the GT350. Factory invoices show that 28 cars were shipped with
factory-installed Paxton superchargers. The reason this was not a more popular
option is because in 1967, a GT500 only cost $200 more than a similarly equipped
GT350. The Paxton option, at $549, was more than twice as expensive.
These production figures indicate that Shelby American never received the full
order of 500 Paxton supercharger kits Carroll Shelby originally committed to in
1965. Although Paxton supercharger hits were offered through Shelby American’s
parts catalog until 1969, it is highly unlikely that 461 Paxton kits were sold.
The actual number is probably somewhere between 50 and 100.
This particular Paxton supercharged Shelby GT350 offered here, #SFM6S2031, was
originally finished in red, and was shipped to the Marshall Motor Co., in
Maryland Heights, Ohio) on 5/26/66. It was purchased by John W. Davey (Kent, OH)
on 6/29/66, or David A. Taylor (Cleveland, OH) on 8/23/66. The car was later
purchased by John S. Brookes (San Antonio, TX), and thereafter by Wayne Cropper
(San Antonio, TX). At some point the car was painted maroon. Shelby American
World Registry, 1997, page 536.