1961 - 1963
Series BT7, BN7 and BJ7
This model often causes confusion for those shopping for an Austin-Healey because there are actually two very different models with this same model name. The first "3000 Mark II" was basically the same as its 3000 predecessor except that power was increased by the addition of a third carburetor (previous big Healeys had two) and the grill was changed from horizontal to vertical bars. Otherwise it's very much the same car. This model also came in a four-seat version still called Series BT7 (5,096 built) and a two-seat version still called Series BN7 (just 355 built, making it the rarest production Austin-Healey and the last strictly two-seater).
Note however that the three carburetors proved troublesome to keep tuned, and even the British Motor Corporation made a tacit admission of this when, in early 1962, they offered a kit to convert the triple-carburetor cars to two carburetors.
Also in early 1962, a Series BJ7 car (6,113 built) was introduced which had the marque's first roll-up windows and a curved, wrap-around windscreen and pivoting wing windows. It retained the vertical grill bars but reverted to two carburetors. Also very importantly, this model was the first big Healey with a more or less permanently attached folding top that provided real weather protection. It is sometimes referred to, especially in Great Britain, as a "Mark IIa" to differentiate it from the earlier version of the Mark II, but "IIa" was never an official name.
Therefore, you have a choice of a 3000 Mark II roadster that came with three carburetors and either a two-seat or four-seat configuration, or a 3000 Mark II convertible with two carburetors and four seats.
Upside: Still the same tremendously handsome car; exclusivity of three carbs on the roadsters (Series BT7 and BN7); good weather protection on the convertible (Series BJ7).
Downside: Three carburetors can be tricky to get tuned and keep tuned; creature comforts still few in the roadsters; BJ7 is a transition model and usually viewed as such.
Bottom line: Three carburetors are distinctive but probably not worth the trouble. The convertible, Series BJ7, is a bit of a sleeper as most people opt for the later BJ8 Series cars (discussed below) with its more luxurious interior, while the BJ7 is mostly the same car as the BJ8 and usually available for less money. Avoid the tri-carb cars unless you're willing to make the commitment. Consider the BJ7 Series car if you want the better weather protection and would like to potentially save the several thousand dollars premium for a BJ8 Series car.