ok quick run down , click click clicking noise would be low voltage . if you get a single click from the starter then most likely its in the starter, try turning the headlamps on and cranking if the lamps stay on strong and you get the click your new starter has a issue ( it does happen) those buicks often had a double positive cable and they would get a poor connection between the cables so the car would power but not the starter. there is a main ground on one of the front bell housing bolts that could be loose if the transmission has been out. I have seen the neutral safety switches loose on those as well but you wouldn't get the click .