ACL Ford 4 2300 (Single Spark Plug engines) Race Series Engine Crankshaft Main Bearing Set

ACL has been making engine bearings for a long time, and their Race Series is a popular choice for builds that need a bit more than stock. They use well-built materials and have tight tolerances, which is crucial for oil control and preventing premature wear. For your 1979 Mustang with the 4 2300 engine, these bearings are sized at 0.010 inches undersize, meaning they're designed to be used with a crankshaft that has been machined down by that amount to ensure a perfect fit and optimal clearances. It's always a good idea to check with your machine shop to confirm the exact specifications needed for your rebuild.