I was wondering if overboring creates any extra power for having a larger surface area, or does it just regain lost power from the the cylinder as it is worn and honed? Just wondering whether its worth doing, i honed the head quite hard when i did top end as when i bought it in April from my mate the piston had scored the head quite bad. Its running fine but was thinking of doing the porting (been watching the Ken O Connor videos!!!) and was wondering whether to have the head overbored. Cheers