For Chevy V6 3.8L 4.3L Ready to Run Electronic Distributor (Vacumm) Black Cap These Cast Body Ready-to-Run distributors are the Perfect upgrade for your outdated and worn out stock distributor. A maintenance free magnetic pick up inside the distributor used to trigger state of the art ignition module under the chrome cover. The increased output of this self contained ignition easily outperforms stock ignitions and helps to smooth out the powerband from idle to high RPM. For stability and endurance, an oversize steel shaft spins in a top mounted sealed bearing while an extra-long sintered bushing guides the shaft at the bottom of the housing . To increase gas mileage, we included a vacuum advance assembly, and you can tailor the mechanical advance curve to suit your engine.