986s (lower 's' to mean base & S Boxsters) have plenty of IMS issues too. 2001 was a particularly bad yr for IMS failures on Boxsters. It was just a bad design in that era. And until the cottage industry came along with their solutions, your only option was to pay Porsche to put a new engine in and reset the clock on when / if the new engine would blow, as the "new" engine had the same bad designed IMS in it. Not a cost effective way to spend $15K.
What also makes things confusing is in this era, 996s had a 3.4 ltr engine with the bad IMS. Then when the M97 comes out for the 987, it's 3.4 ltrs too but has the new design. Adds to an already confusing situation.