I should have said "the 81 Imperial as originally built". Sorry. Dick Benjamin > Both my 81 Imperials have been converted. No more computer. It has a vacuum > advance. > Syuart Somers > > Just for accuracy, the 81 has neither vacuum advance nor centrifugal > > advance, and with no moving parts other than the rotor shaft, there is > very > > little opportunity for wear or deterioration with age or usage. Of course > > it has no points or condenser either. All of these functions are > performed > > by the computer - the distributor merely senses the rotation of the rotor > > shaft and distributes the secondary voltage to the spark plugs. > > > > Dick Benjamin > > > I used a Mopar Ignition on My 81 Imperials. Pulling out the distributor > > > takes a second. It is easier to do that than fiddle around inside the > old > > > one. You can count on a 30 year old distributor to have a weak vacuum > > > advance or wobbly bushings. > > > > > Stuart Somers