First number is case/ line bore size, second number is crank size and third number is thrust size.
Manufactured in Mexico by Silverline – an Original Equipment Supplier. Top engine builders will tell you that all aluminum center main bearings can cause increased bearing wear or premature failure and will eventually pound-out the center main web of the engine case due to the bearing’s softer construction. The cure…new Silverline Engine bearings – with STEEL Backing and an Aluminum Face. OEM Quality Main Bearings with STEEL Backing.