well engine block i`ve never seen one on a shee, j/k. but you can however bore out the sleves in the jugs, about .030 is about the biggest you can go if i`m not mistaken (some of you 2-stroke guys help me out) or if you want to get really crazy you can go to a place like trinity and get a big bore kit http://www.trinityracing.com/product...hee500kit.html

 

.60 if im not mistaken, i maybe wrong though

 

woops .060

 

I thought it was .100 over, and .080 over if you didnt want it to blow.