If anyone is looking to do a new top end ( Piston ) Etc, As long as its not cracked, you will need new rings and gaskets, and save yourself a few hundred $$ and send it out for piston coating, , This is the first thing we do in our bikes now, even new, it cost about $40.00 for 2 strokers, and a little more for the 4 strokers as they coat the top with ceramic,
Do some research at this site, I dont get a commission, just a guy who has an awesome product and last forever, if you have an excessive clearance issue, this is your fix, I have had 6 Trials bikes done, And about 25-30 racebikes done, both Motocross and Enduro 2 and 4 stroke.
This is a proven product and saves you a ton of cash......
Here is the link http://line2linecoatings.com/products.html
Once again, I have no affiliation to them, but you could say that you heard it from Ron in Illinois he will know