Mix sugar, flour and milk in a saucepan and cook over medium heat, stirring constantly till bubbly around the edges.
Remove from heat. Stir a little (maybe a half cup - I never measure) of the hot mixture into the egg yolks and mix together. Add back into saucepan and continue cooking and stirring till thick.
Remove from heat, add vanilla and 1 1/2 cups coconut.
Pour into baked pastry shells. Top with meringue and sprinkle with remaining coconut.
Bake in a 375 degree oven until lightly browned.
NOTE: I make my meringue by beating the egg whites till foamy, adding 1/4 tsp. cream of tartar. Continue beating till mixture starts to thicken, then add 6 tblsp. sugar, one spoonful at a time, beating after each addition. Beat till stiff peaks form. Pile on top of filling, making sure to spread all the way to the edge of the crust.