The '65 Chrysler 300-L is accepted by some aficionados of the Letter car, but rejected by others. Some say the 300-L is not a "real" Letter car because Chrysler strayed away from the original concept of the 300, while others argue that it maintained the image. Both sides make a strong case for their respective arguments.

The 300 as originally conceived was something of a gentleman's hot rod. It was fast, handled well, and was luxuriously appointed. The high-priced 300 occupied a very narrow market niche, but it helped build an image for the company that produced it. The first version of the car, the '55 300 (or C-300), quickly provided good publicity for the company with NASCAR wins. The trend followed the next year with the 300-B. At first, the 300 was offered only as a two-door hardtop, but by '57, a convertible was added to the line. Performance capabilities continued to be upgraded through succeeding years, and reached a new level with the "F" variant in 1960. The standard dual four-barrel 413 by this point acquired Ram Induction which was comprised of a series of tubes leading to the carbs mounted on each side of the big V8. (These tubes provided a supercharging effect, which served to boost performance.) The top-performing '60 models were the limited-production four-speed equipped cars-most of which competed at the Daytona Speedweeks. The ram setup remained as standard equipment through 1961, although the four-speed option was dropped; however, a three-speed manual was optional.

Model year 1962 brought significant changes to the 300. By this point it had developed into the 300-H and something else called the Sport 300. Here lies the source of the dispute concerning the 300-L. The Sport 300 replaced the Windsor series in the Chrysler lineup. As had been the arrangement for the Windsor, there were four-door versions available in the Sport series. Marketing wanted to capitalize on the image the 300 series had created for the company by applying the name to what essentially was still a Windsor. Sales of the Windsor had been in decline for a while; stealing the 300 image and name for the car to boost sales seemed like a good idea to change this situation. From a production standpoint, the decision proved to be justified; sales of the Sport 300 were higher than the previous year's Windsor lineup. To some Letter Series fans, the introduction of the "cheapened" 300 defamed the character of the car. Adding insult to injury, in their opinion, was the fact that Sport 300s could be ordered with nearly all of the Letter Series equipment. To the 300 purist, it was inconceivable that a Sport 300 four-door hardtop could be ordered with a performance engine that had always been the exclusive property of the Letter Series cars. Nearly all of the standard "H" equipment was listed as an option for the Sport version. Another reason for the uproar had to be that, outwardly, the 300-H and the Sport 300 looked almost identical; only subtle details differentiated the two cars exteriorwise. As a result of the Sport model's existence, the Letter car declined in popularity. In 1962, sales were two thirds of the '61 production, and model year '63 was even more severe.

Although '64 production increased ninefold, the larger figure is often misinterpreted. Some would say the purists were returning to the 300, but what really pushed sales higher was that many of the Letter car's formerly exclusive features from past years became optional. As the result of this action, the 300-K's base price was about $1,100 lower than that of the 300-J. The lower price brought sales from people who would not have considered buying the car in the past.