No rtv on mine, used a cork gasket. Got my pan plug kit from JEGS in your neighborhood (Broad St in Columbus). Crossover pattern and several passes to torque to specs... NO LEAKS. Be sure to hold plug mount when you loosen to change fluid.
Bandit - Jegs' number vnd# 130 part# 80250. It is a B&M 80250 "automatic drain plug kit" I paid $6.69 3 years ago. Step three cautions on removing plug. Mine is installed on the left hand rear bottom. When I change fluid the car gets jacked for best drainage
p.s. I was @ the Buick show in a show in Dublin (Len Imke / Arthritis Foundation) Sat. were you there? Are you going to the BPG meet in Salem OH Aug 12 - 15?