Want to build a powerful Ford engine for your vintage muscle car, street rod, Fox - body or late - model Mustang A Ford Performance short block is the perfect foundation. Ford Performance Engineers have taken care of the toughest part of building a new engine by designing a strong a durable short block that offers a wide range of power possibilities. We use only the best parts for our short blocks, like a forged steel crankshaft, forged H - beam connecting rods with floating piston pins, forged Mahle pistons, and the Ford Performance BOSS block. And every Ford Performance short block is hand assembled in the U.S. with performance clearances - these aren't assembly line truck engines made by machines WARNING This part is designed and intended for competition use only. It should not be installed on a vehicle that is driven on public roads and highways. Installation of this art on a vehicle driven on public roads and highways is likely to violate U.S. and Canadian laws and regulations relating to motor vehicle emissions.