My E23 has 250k on it... I also was looking into the chip option, and am also planning on doing a rebuild in the next year or two (depending on certain circumstances). I currently have no issues other than vacuum and heater core (in process of fixing). Would you recommend waiting to chip until after the rebuild & tranny swap (going manual), or should it not make a difference? Do you have a link to a provider for the Wokke chips?