Are there (or will there be) any rules for progressing beyond the level caps in the core book? I suppose that would be considered "epic" level game play :)
“The Player's Companion extends the core rules by adding a series of new classes, the dwarven machinist and spelunker, the elven ranger, and some human classes - mystic (monk), shaman (druid), and priestess. I'll come out and say it though, the thing that got me fired up with the book-love was the extensive list of templates. (I think they claim there are 144 of them). An ACKS template is basically some pre-selected options that speeds up character generation and gives the character a bit of early flavor. ACKS supports the old school roll-and-go - it's got basic 3d6 in order for abilities and simple classes, like classic D&D. The templates take it the rest of the way, by adding a preconfigured set of starting equipment, starting money, and suggested proficiency selections.”
No, there are no rules for progressing beyond the level caps, and there are no plans to support it. 14th level is the absolute maximum level for characters in ACKS. A 14th level character is powerful enough to rule a world-spanning empire!
But honestly, if you want higher level play, there are plenty of resources to figure it out. LL and BECMI will give you the xp charts for example.