Move from 802 N to 802 A/C

I have an early 2008 iMac that uses 802 N for wifi. Recently, I upgraded the router to Apple's 802 A/C Extreme. Is there any way to change my iMac to use 802 A/C?

An early 2008 iMac? No, not internally.

I don't think there's any external solution either -- a dongle would be likely to use USB, but that machine won't have USB 3.0 so you wouldn't see any speed advantage. I'm not saying "buy a new machine just to get 802.11ac speed," but .... you know, that iMac is eight years old now ... it's overdue for a new(er) replacement.