0.25 main bearings Toyota 1982-1996 21R, 21R-U, 22R-TEC 2367cc ACL Aluglide ACL Race shells are designed to work in the most extreme conditions and the most demanding engines. Thanks to many years of experience in the production of bearings, each set is perfectly matched to the engine. The advanced technological process allows the bushing to adapt to the deformation occurring at high revolutions and helps in the formation of hydrodynamic oil films. This technology, combined with the advanced geometry of the bushings, makes them ideal for heavily stressed engines. : 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)