If you are spinning your engine above 7500 rpm it is recommended to replace the stock balance shafts with neutrals or to completely remove them. These bushings are used to plug the balance shaft oil feed holes in the block. They have a 5/8"-18 thread so you can install them with a slide hammer and remove them the same way if you want to go back to stock. They are made from 6061 aluminum.
When you install these in the block you have two options. If you are running an electric water pump you will need these two bushings and our front balance shaft plugs. You can then delete the short chain completely. If you are running the stock water pump you will need to retain the short chain. We do this by machining off the front part of the stock balance shafts. They are then used as an idler for the gear to ride on.
Core returns have to be received within 30 days for a refund. Outside of 30 days we can only offer store credit. Cores must be in good usable shape to receive your refund. A good core will have no damage to the threads or bearing surface. If your fingernail can catch a groove on the bearing surface that shaft is no good. Core charge is $65