How far is a distance? The bolts on 40mm ones are closer together than 65mm ones. 40mm have a single pad retaining pin where 65mm ones have two (afaik)
pictures of potential bikes on the interweb etc... i know that discs changed midway through 748 production from holes to keyholes and i believe calipers did too from 40 to 65 to trying to ensure i know what im looking at
The shape of the mounting bracket on the fork leg is quite different, apart from the spacing the 65mm mount is at a different angle. 40mm (916); 65mm (996); They changed with the release of the 996 (1999) but I would imagine it is possible some post '99 748 may have had 40mm due to getting rid of old stock...
