The 2.5 L inline-4 was a abbreviated version of the 258 6-cylinder engine stretching to 3.875 inches (99 mm) and extended to 3.188 inches (81 mm). The block basically resembles the same as the inheritance 258-cubic inch engine with a larger bore and the two focused cylinders removed. The head emphasized a makeshift combustion chamber and port design that was used in the future on the 4.0 L - the 2.5 L I-4 head was embroidered by two cylinders in the middle.