Adapter For Mack Engines - 672, 673, 675, 711 Series in-line 6 cylinders. If you're servicing these specific model engines, you'll want to get this adapter. Hein Werner offers the widest variety of adapters for their heavy truck engine stand to allow you to handle any engine that comes your way. Be the most versatile shop in your area and don't turn any work away because you don't have the proper tools for the job.. Premium features and made in America. Give us a call today.