All E-87': Have mechanical advance. Actual advance curves vary from year to year.

E-68': Extra small distributor body, vacuum advance (correctly called "non-smog", also sold as "non-USA").

69'-74': Extra small distributor body, but with vacuum retard.

75' & early 76': Small distributor body, completely redesigned, very good quality points distributor. Vacuum retard.

Late 76' & 77': Same as previous, but with vacuum advance.

78': Redesigned w/ Medium size screw down, waterproof cap, electronic ignition. Vacuum advance & retard.

79'-80': Dual diaphragm advance. One big advance (approximately 8 degrees) stage for normal operation, small second stage (approximately 4 degrees) for extra advance at hi-altitude (High altitude compensation system). Electronic ignition system.

81'-87': Distributor body redesigned to use large cap. Same dual diaphragm advance introduced in '79. Electronic ignition system.

88'-92': Distributor redesigned without advance. Distributor pickup is a crank angle sensor, advance curve is controlled by EFI computer.

Information contributed by:
Jim "JimC" Chenoweth
TLC Performance
Lancaster, Ohio, USA
Ph. 740.862.2604

*See something missing, wrong, or incomplete? Please let us know!