Sivlerline is an OE supplier of top quality engine bearings. Most top engine builders will tell you that all aluminum center main bearings can cause increased being what or premature failure and will eventually pound out the center main web of the engine case due to the bearings softer construction. The cure, new Sivlerline engine bearings with steel backing and an aluminum face. These OEM quality main bearings have steel backing for long life and minimal wear. 

Several combinations available. This combination is for a Line Bored Case with a Machined Crankshaft!