use your senses
touch ..before you get worried ..the output shaft is supposed to wiggle , the input should turn
eyes ..if case is cracked its probably no good , look inside the front seal at the pump ..it has two square tanges that slide into the converter. broken or sheared corners on those tanges is not good
look for the BQ label if hotair or BRF for intercooled , any other trans setup wont work well in your buick without swapping over the wiring harness , trans gear switches , governor , servo and valvebody
ears ..they wont do you any good
nose ..if the fluid smells burnt it probably needs a rebuild
mouth ...i dont recommend licking it or tasting the fluid