Hi! I was wondering if anyone out there knew if an MC (or other piston) has a bore of 86.5mm? I am hoping to find a suitable Audi piston to fit my Porsche 924. My porsche has a bore of 86.5mm and a stroke of 85.4mm Am I wrong, or does an MC share these same specs? Any help would be appreciated. Jay 82 924 (needs slugs)