Main bearings 0.25 Ford 1989-1997 140, 153 (2.3L, 2.5L) ACL ACL Race shells are designed to operate in the most extreme conditions and the most demanding engines. Thanks to many years of experience in the production of shells, each set is perfectly matched to the engine. The advanced technological process allows the bushing to adapt to the deformation occurring at high RPM and helps in the formation of hydrodynamic oil films. This technology, combined with the advanced geometry of the bushings, makes them an ideal solution for heavily stressed engines. Most bushings are also available in several other dimensions: STDX -0.025 mm (looser than nominal) STD +0.000 mm (nominal) +0.025 mm (tighter than nominal) +0.25 mm (first shaft grinding) +0.50 mm (second shaft grinding)