ops:Correction for ya...The 300 Letter Cars started in 1955 and ended in 1965. 1965 was the "L" car. The 1966 was supposed to be the "M" car but was dropped at the very last until it came out in the '90's on the new platform. So the 1966 should have been the "M" but wasn't. In 1966 there was the "TNT" package which had the 440 and the tilt/telescoping steering wheel and the floor console shifter with either the Tach or the Vacuum Gauge, front disc brakes and larger 15" wheels and hub caps as an option. Here's a pic of my '66 which is now in FL...