Making their first appearance in September 1966, the 1301 and 1501 were a very skilful update of the 1300 and 1500. The front of the car was extended by 6.9 cm, using a new curved bonnet, grille and bumper. The front wings were the same as the outgoing model, but with side cut out to accommodate the wrap around front indicators. The rear of the saloon was extended by 13.5 cm, giving the cars a long and elegant side profile and a massive boot. While the estates retained the 1300/1500 rear styling, they also benefited from the revised front styling. Marketed as the new BIG Simcas in the UK with the low, European line, the cars certainly looked attractive, arguably the best looking of all Simca saloons. The interiors were also improved, with a new dashboard and fittings. The range consisted of LS, GL and GLS versions of both 1301 and 1501.

1969 saw the introduction of the 1501 Special, with a tuned version of the 1475cc engine, auxiliary driving lamps and sports steering wheel. This was followed in 1970 by the 1301 Special which, together with other 1301s, had a modified version of the 1475cc engine in place of the old Aronde Rush engine. The last link with the Aronde era had gone. A new and very sporty black grille incorporating rectangular auxiliary driving lamps was introduced on the 1501 Special, and by 1972 this was used on all 1301s and 1501s. Also in 1970 the instrument panel was redesigned and featured easy to read round speedometer, tachometer and clock. In 1970 Simca Automobiles became a wholly owned subsidiary of Chrysler Corporation, and the company name was changed to Chrysler France. In October that year the individual S I M C A letters on the cars were replaced with small rectangular badges saying SIMCA, with the model name being shown on another rectangular badge with a red background at the rear of the car. The red on these badges had a great propensity to fade, so after a few months of ownership you could not tell what model of Simca you were driving!

Sales of all Simcas in the UK grew rapidly in the early 1970s as the benefits of all Chrysler UK dealers stocking Simca cars trebled the outlets for them. 1301s and 1501s became familiar sights on British roads. In 1972 the range was slimmed down to just the 1301 Special and 1501 Special, both available as saloon and estate. Engines were producing 66 bhp and 74 bhp for the 1301 and 1501 respectively. The last cars were built at the Poissy factory in July 1975, but continued to be sold into 1976. Total production was 605,815 1301s and 236,263 1501s. The replacement was the futuristic looking Simca 1307/1308 (Chrysler Alpine in UK).

As with the 1300 and 1500, the 1301/1501 models have a strong following in France and Germany. In the UK only about 10 of each type are known to the Club, but there are probably a few other survivors waiting to be found. As with most of the older Simcas, mechanical parts for both the 1300/1500 and 1301/1501 are not too difficult to source, but body panels are becoming scarce.