Nice summary of the '66 season and rules. The Miles car looked almost factory stock (minus bumpers). It doesn't appear to be one of the factory Darts but the class was set up for low budget entries.
'66 Trans-Am History
Both the Barracuda and its Dodge "cousin" the Dart were early players in this series, which was the longest continuously running road racing series in the US. Note some of the significant pilotees:
Chrysler and the 1966 Trans-Am Season
In 1966, The SCCA introduced a new class that allowed for head to head competition between Dodge Darts, Plymouth Barracudas, and Ford Mustangs. The rules were simple: competition was allowed between "Production Touring Cars" with a max wheelbase of 116". There were two classes, the "2 litre and under" class and the "2 litre to 5 litre" class. The Trans-Am class rules allowed few modifications to a production car. Drivers were allowed to remove bumpers, rear seats, and floor mats. (Full interiors with functioning windows). Mufflers could be replaced with straight pipes and different rims could be used so long as the stock rim diameter and width were maintained. The 2 litre class saw competition between Alfa GTA's, Ford Lotus Cortinas, Austin Mini's, BMW's, Renault Gordini's, Volvo 120's, as well as entries of Volkwagens and Saabs. The 5 litre class hosted Plymouth Barracudas, Dodge Darts, Ford Mustangs, and Chevrolet Corvairs (out-cubed by the Ford 289 and Chrysler 273).
Mopar teams in the 1966 Trans Am season were:
Team Cars Drivers
Dart #9 David Pearson/Brock Yates
Team Starfish Barracuda #14 Richard Petty (a.k.a. Dick Petty), Charlie Rainville
Team Starfish Barracuda #15 Scott Harvey/Bruce Jennings/Les Netherton
Barracuda #16 Steve Durst/Albert Schall
Group 44 Dart #44 Bob Tullius/Tony Adamowicz
The first Trans Am race was at Sebring on March 25, 1966. It was the Dodge Dart driven by Bob Tullius that finished 1st in the "over 2 litre" class. Tullius would rank 3th overall in 1966, and would go on to have another 1st place and a 2nd place finish. Bob Johnson raced a Barracuda (before switching to a Mustang mid-season) and finshed 2nd overall in season points with 2 first place victories The overall (points leader of both the 2 litre and 5 litre classes) first place went to the Kwech/Andrey Alfa GTS team.
Bob Tullius' race team was called "Group 44" and had a good sponsorship with Quaker State for several years. Tony Adamowicz was hired as a 3rd driver for the team with Tullius and Martinshop. Group 44 raced Triumphs (TR4's, and later Spitfires) as well as the 1966 Dodge Darts. The team won the 1966 Marlboro 24hr Endurance race in car No.4, a 1966 Dodge Dart, driven by Adamowicz and Tullius.
For 1966, Darts and Barracudas were campaigned with good success in the series overall, and, for the most part, dominated the "over 2 litre" class. The cars raced were Dart 270 model coupes or GT coupes with 273/4bbls. Rules allowed for the use of any engine component available over the dealer parts counter, but this allowance was not utilized by the manufacturers in 1966 like it was later in the 60's by Ford and Chevrolet.
For whatever reason, Dodge and Plymouth dropped their factory backed Trans-Am support for the 1967 season. It was possibly due to the small cash winnings, or the fact that road racing crowds were a fraction of the size of the NASCAR and the drag racing crowds. It has been said the reason Chrysler pulled its factory support was that Mopars gave away too many cubes to the competition, but this an unlikely reason because Mopar dominated the 66 season! At this point GM had no involvement in the class (other than privateers racing corvairs), and only competitor was Ford, who was racing a 289. It wasn't until 68/69 when everyone maxed the cube limit. Chevy, Ford and Mercury each witha 302cid V8, AMC with a 304cid V8, and Ponitac with a destroked 303cid V8.
(From Slotforum.com post 16, 2006)