In a medium saucepan, bring cream to a boil; remove from heat, and add chocolate and bourbon. Let stand 3 minutes; whisk until smooth. Transfer chocolate mixture to a medium bowl, and refrigerate, uncovered, until thick and firm enough to spoon out in mounds, about 2 hours.
Line a rimmed baking sheet with parchment or waxed paper. Drop level tablespoons of chocolate mixture onto baking sheet. Refrigerate chocolate mounds until firm, 30 minutes.
Place pecans in a shallow bowl. Using hands, roll each chocolate mound into a ball; roll balls in pecans, pressing lightly to adhere, and place on baking sheet. Refrigerate truffles until set, 30 minutes to 1 hour.
To make sure the chocolate does not melt, work with a few truffles at a time (keeping the rest refrigerated), and roll them in the nuts quickly.