if the valves wernt bent to an extent to jam them in the guides they should be ok,bummer man!,any time i put any engine together ill rotate it by hand to make sure this dosent happen,,the starter motor isnt so forgiving,buy new or find good used valves(how many bent?),keep the unbent ones in the same places and with an oiled guide try the new valve in the guide,raise it off its seat about how high it would lift by the cam,wobble it back and forth there will be a little movement but shouldnt be obvious or flex the guide seal,you might have to get seats cut with new valves,old ones you can be lucky and they go straight in,,good luck.