LOL
Thats a joke now?
Everyone who can count a little bit know this.
Stock crank = 67.4
Stilo crank = 78.4
Difference 11mm.
Pistons have to be 5.5mm shorter. Now meassure a stock piston and you know it what you need.
Its ok if you say its a secret where the pistons from, but everyone who will build an engine serious need this info, mate.
You use conrods with stock length?