Cool read on the Paxton powered GT-350's
I found this cool article on the GT-350's that were sold with the optional Paxtons.
http://www.motorsportsmarket.com/pag...ail.asp?car=48
Quote:
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.
