hi. the cam timming will be corect as long as you put the dist in at tdc. think about it. the crank turns twice to the cam once. so for every time that you turn the crank one complete turn you turn the cam 1\2 turn. so install the cam at 12 or at 6 oclock won't matter as long as you have the crank at tdc. and no you won't gain anything by reinstalling it.