5150 High Performance Coated Rod Bearing Sets are made for the demands of high performance engine builds. Treated shells and coated by Calico to reduce friction, these bearings allow your engine to generate more power and resist "spinning" under stress. These coated bearings also have thermal resistant properties that not only perform in high HP applications like forced induction or race use, but also help prevent sudden engine failure in the event of oil pressure loss. 5150 bearings have proven themselves on and off the track, lasting longer and outperforming other bearings on the market. Due to the specialized tools needed, professional install recommended. Please check your tolerances and size before installation.  There are no returns available on any engine bearings.