I can't tell you from experience, only research. From what I've gathered, 901 and kr8(the new designation on the forum pronounced "kreight") batts and cartomizers/attys are physically interchangable. However, us 901 users have that little air hole at the front of the atty that the kr8 doesn't have. Thus there's not enough airflow from the 901 into the cartomizer.
I've seen a few fixes written about; grinding a groove
through the 901 batt connector (apparently this resembles that of a kr8), the "bent staple" often used for non-connecting batts, Vapor Country and NHaler have adapters to put a cartomizer on a 901 batt connector.
I have ordered some inexpensive 901 manual battery charging extenders. I figure to drill a small air hole as in the atty and I should be good to go. I may try the dremel slot through the connector also.