The Austin Healey 100 was the first of the three models which had followed, namely the Big Healeys. This name was given to the three models to set them apart from the smaller model, the Austin Healey Sprite. The first 100s series had started with the BN 1. The car was equipped with the same I4, 2660 cc engines rated at 90 bhp, and had the same transmission as the A90 had, but with time, it had been changed to a 3 speed unit with overdrive. The front suspension was independent which used a coil spring, the rear consisted of a rigid axle, steering was by lever and cam systems.

The BN 2 followed the production of the BN 1. This model had a 4 speed manual transmission fitted right within it, along with overdrive gears. The BN 2 was the modern version of the BN 1 as the tires of the BN 2 were a slight bit bigger compared to the BN 1; the BN 1 and N 2 had different rear axles, and had an option for the paint. The color options for BN 1 included Spruce Green, Reno Red, Healey Blue, Florida Green, Black, Old English White and about 50 Gunmetal Grey cars. Whereas the BN 2 two-tone colors included White/Black, Healey Blue/White, Reno Red/Black, Florida Green/White and Black/Reno Red.

A new 100M model had now come out of the production house; this was a more modified version of the Austin Healey 100 series. The car had larger carburetors, 8.1:1 compression pistons, cold air box which was used to increase air flow for the carburetor and a high lift cam shaft. The engine produced 110 bhp at a rpm of 4500. The suspension in the front was now stiffer than the one before, and the bonnet had now gained louvers, and a bonnet belt to go along. About 70% of the production of the model was finished with the paint scheme of the two tones this also included unique color schemes: White over Red and the other in Black over Pink.

In July 1956, the last BN 2 model from the Austin Healey 100s series had been built, ending at a total of 4604 BN 2s being produced including the 100M models as well.