1941 GMC Tractor-Trailer. GMC Super-Duty Engines Are Still The Strongest Pullers Of All Published April 2, 2024 at 1495 × 2048 in GMC ← Previous Next → 1941 GMC Tractor-Trailer. GMC Super-Duty Engines Are Still The Strongest Pullers Of All Source: www.flickr.com / Alden Jewell