I was thinking of buying this for my 64 VBB. I figure a little more displacement would be nice without dropping all the money on the Pinasco kit.
http://cgi.ebay.com/ebaymotors/Vespa-performance-cylinder-piston-kit-VBA-VBB-VBC-VLB_W0QQcmdZViewItemQQ_trksidZp4999Q2ec0Q2em14QQhashZitem20ad1e9afcQQitemZ140343417596QQptZOtherQ5fVehicleQ5fParts