Has any one heard of this, it was posted on the old site a while back they said to use Polaris 785 pistons which only come in one size 69.7mm. This gives you an extra bore over the oem max size and could possibly be done with the stock sleeve but not sure my cylinder is sleeved and Im at 69.75mm using a Polaris SL750 piston. SL750 Pistone are available up to 72.5mm my sleeve will only make it to 72 but it gives a big selection of larger sizes that will go up to a 305 i believe im at 270 plus the Sl piston is about 17 grams lighter than the smaller 785 piston. The only issue is the location of the piston ring pins they fall right in the intake port and could be an issue but so far so good.

THe 785 piston WAS really cool................     ITS not any more unless you can find NEW OLD STOCK from somwhere other than Wiseco. They changed castings, no longer cut the Lightening windows and there is no Coating anymore. Use a Honda piston, There less likely to F''' with those.

BE careful on a Piston that unshrouds in the intake when they wear some is whaen you will have a problem, keep on it maintenance wise with good rings.
 

all depends how its set up you will need a spacer but you'll have to measure for the size.