In May 1965, Shelby American was starting to look ahead to the '66 GT350s. By then, it knew that minor changes were in store to differentiate the newer models from the previous '65s. In particular, sidescoops and quarter-windows were planned, but Shelby needed to know how much work would be involved to install the additional parts. That's where 5S319 came into play.
Pulled from the regular GT350 assembly line, 5S319 would remain at Shelby American for three years, from May 1965 until May 1967, according to Shelby American Registry records. During its tenure as a prototype, 5S319 was fitted with sidescoops and quarter-windows, which would eventually find their way onto '66 GT350s. At some point, it also received a Cobra emblem on the glove compartment door, underride traction bars (brackets for the override versions are still on the car), a '67 Shelby wood steering wheel, a '67 AM/eight-track radio with door speakers, and a prototype carpeted rear shelf.
Interestingly, 5S319 was also used to fit a prototype rear spoiler, which didn't make the cut for the '66 GT350. However, the rear spoiler would become an integral part of the design changes for the '67 Shelby Mustang.
It's also interesting to note that, during the summer of 1966, 5S319 served as a loaner vehicle to Charles "Chuck" McHose, the Ford stylist/designer who was sent to Shelby American to style the '67 Shelby. Shelby American records show that McHose was rear-ended by a drunk driver in July 1966, severely damaging the rear of the GT350. It had less than 4,000 miles.
After repairs, 5S319 languished at Shelby American as a used muscle car. It was advertised by Shelby American as part of a used car auction in December 1966, then picked up by Shelby's Hi-Performance Motors in El Segundo for $2,000 in May 1967. After going through a couple of owners in the 1970s, 5S319 was purchased in September 1980 by Jeffrey Childs, who has owned the car for the past 30 years. Most of that time was spent in storage.
Earlier this year, 5S319 was pulled out of storage and freshened up by Mark Knass in preparation for its role as a feature car for the Mecum Auction during Car Week in Monterey, California. At our press time, it was scheduled to cross the block around 2:30 p.m. on Saturday, August 14, during the televised portion of the auction. Watch for it on HD Theatre, a Discovery Channel network.