Combine butter, syrup and sugar in saucepan. Heat until butter is melted and sugar is dissolved, stirring frequently. Remove from heat. Slowly add beaten eggs, while stirring hot mixture rapidly. Add vanilla. Mix thoroughly. Place pecans in unbaked crust. Pour egg mixture on top.
Bake at 375* F for 10 min., the turn down to 350*F for 45 to 50 min.