Melt butter in large pot over medium heat. Add garlic; sauté 2 minutes. Add breadcrumbs. Sauté until golden brown, about 4 minutes. Remove from heat; mix in parsley. Season stuffing with salt and pepper. Cool completely.
Starting at 1 long side, cut each tenderloin lengthwise almost in half, stopping about 1/2 inch from opposite long side. Open tenderloins like books. Sprinkle cut sides with salt and pepper. Pack half of stuffing on 1 side of each tenderloin. Fold plain side over stuffing.
Slightly overlap half of bacon slices on sheet of parchment paper, forming rectangle equal in length to 1 tenderloin. Place tenderloin at 1 edge, across bacon ends. Using parchment as aid, roll up tenderloin in bacon. Using kitchen string, secure bacon around tenderloin, tying at 1 1/2-inch intervals, then tie once lengthwise. Repeat with remaining bacon and tenderloin. (Can be prepared 1 day ahead. Wrap tenderloins and refrigerate. Let stand at room temperature 1 hour before continuing.).
Preheat oven to 400°F Pour enough oil into large skillet to coat bottom; heat over high heat. Add 1 tenderloin. Sauté until bacon is brown, turning often, about 10 minutes. Transfer to rimmed baking sheet. Repeat with second tenderloin. Roast until thermometer inserted into center of each registers 130°F to 135°F for medium-rare, about 30 minutes. Transfer to platter. Let stand 15 minutes. Cut off strings. Cut tenderloins into 1/2-inch-thick slices.