All the modern tanks seem to be nearly the same size, which is a bit over 2". Doesn't seem to matter which brand of 9oz. Al. tank, they're just relabled from various suppliers.
3 modern 9oz. tanks:
2.10"
2.12"
2.13"
(have to measure in several different areas (and not on top of a sticker) as they are not perfectly formed).
My one 9oz. steel tank (with the rounded end, not flat like Al. tanks) runs 2.05". Would expect there to be a variation of a few 1/00ths between tanks.
The old school Al tanks are closer to 2", but of the old time 10's, 7's, and 3 1/2's only the 3 1/2's seem to still be in production.
7 oz (from about 1983) = 1.98"
3.5 oz. (current production) = 1.93"