i have heared about a Molossi Kit with 65mm piston. As far as i know you have to modify the cylinderhead. You have to remove the 'step' in the original Gilera head. I just have 'stolen' two pics from Gottfrieds page so you can see what to do. But.... I think you should mount the kit and see where the piston is at top and measure the compression ratio. I hope that someone with more expert knowledge will also send an answer.
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