Shop teacher needs HELP!!!

HI All I need a piston to deck clearance for a 71 cb motor. Is the piston in the hole or os it 0 at the deck? We havent broken the motor appart yet and we are trying to get all our ducks in a row with what pistons we can use in the bike. also I know this seams to be a strange request bit does any one have or know some one who has a v-rod headlight assembly? We have checked out local HD dealers and no dice. Every thing on e-bay is going for more than retail so if any one has any sourses or help for us we would realy appricate it.
also check out the updated site http://niskygarage.logical.net
Thanks in advance
Richie