The ’66 GTO not only broke past sales records, but it is destined to eclipse all future years sales, with 98,946 units produced in all that year. Pontiac tried in vain to market the car as “The GTO Tiger”, but a twisted acronym prevailed and the GTO is stuck with the moniker “The Goat”, which survives to this day. As with previous years two V8 engines are on the table; a 389 cu in (6.4 L) and the 400 cu in (6.6 L) version. The four transmissions offered are a three speed manual, four speed manual, 2 speed automatic and the 3 speed automatic. The tri-power option is discontinued half way through ’66 and is replaced by the XS engine option which would give you the 744 high lift cam and also includes Ram Air. Although the combination develops about the same HP rating as Tri-power, it is not a hit with consumers. There are about 300 of the XS option in total ordered by Pontiac dealerships, but only around 35 of them were actually built by the factory.