Place the dark and golden raisins, rum and orange zest in a small saucepan. Bring the mixture to a boil over medium heat, remove from the heat, cover and set aside.
Meanwhile, pour the cream, milk, vanilla bean and 1/3 cup of the sugar into a large saucepan and heat it to a simmer over medium heat. Place the egg yolks, the remaining 1/3 cup of sugar and the salt into the bowl of an electric mixer fitted with the paddle attachment and beat on high speed for 3 to 4 minutes, until very thick. When the beater is lifted, the mixture will fall back on itself in a slow ribbon. With the mixer on low, pour 1/2 cup of the hot cream mixture into the egg mixture. While stirring with a wooden spoon, pour the egg mixture back into the saucepan and cook over medium-low heat, stirring almost constantly, for 8 to 10 minutes, until thickened (175 degrees F to 180 degrees F on a candy thermometer). The mixture will be thick enough to coat the back of the spoon (your finger should leave a trail on the back of the spoon). Immediately pour the mixture through a fine-mesh sieve, discarding the vanilla bean. Refrigerate for at least 3 hours, until cold.
When ready to freeze, drain the raisin mixture, reserving the rum and discarding the orange zest. Mix 3 tablespoons of the drained rum into the cream mixture (discard the rest). Pour the mixture into an ice cream maker and freeze according to the manufacturer's directions. At the end, stir in the raisins and pecans, transfer to a quart container and freeze.
To toast pecans, roast them in a 350 degrees F oven for 5 to 10 minutes, until lightly browned.