Davis Unified Ignition Distributor Shim Kits

Performance Distributors D.U.I. nylon shims may be necessary to protect the cam and distributor gears from irregular wear--especially if your engine has had the block and heads milled. If that's the case, then the distributor may sit too far down in the motor, which will "bottom out" the distributor on the oil pump. This is a bad situation which puts the gears in a bind and will cause irregular wear and destruction to the teeth of the gears. These high-impact nylon shims are designed to fit between the intake and distributor gasket. Installing a shim with the correct thickness will allow the gears to mesh properly and can prevent costly repairs down the road. Show Less