Pre-Installation Check (this page is from the Mark 10 B ignition
manual, dated 1972)
As the Mark Ten B Ignition System has been designed to provide optimum performance with standard (original equipment) coils, the use of special coils such as transistor or other high ratio coils is not desirable and will actually degrade the performance of the Mark Ten B System.
With the higher output energy of the Mark Ten B, it is important that the high tension system of the vehicle be in good condition. Defective or cracked distributor caps or rotors, which may cause occasional misfire on a conventional system, will generally cause extreme engine roughness with the Mark Ten B unit. Radio resistance wire, (TVRS), if used, must be in good condition or poor performance and hard starting may result. Resistance of those wires must check 30K or below with an ohmmeter to be considered satisfactory. To reduce radio noise sometimes experienced, an inductive high tension wire may be employed. Such a wire is available from Triple-A Specialty Company, 5730 West 51st Street, Chicago, Illinois, 60638.
When any question exists as to the condition of the high tension leads, it is suggested that a replacement high tension harness, including the lead between the coil and distributor, be installed (available at all stores handling automotive accessories).
SPARK PLUGS: To assure proper performance, standard heat range plugs, gapped at .040 should be used with this system. Surface gap plugs are not recommended. Cold range plugs should be used for racing or extremely high speed operation. When installing the Mark Ten B Ignition System during the Winter months in extremely cold climates, it is advisable to re-gap the spark plugs to .045.
BALLAST RESISTOR: The Ballast Resistor (or resistance wire) may be retained or by-passed at the option of the owner. For racing or operation over 5000 RPM, it should be by-passed for optimum performance. The distributor point condenser should be retained in the system.
RADIO NOISE SUPPRESSION CAPACITORS: May be used with the Mark Ten B, but must not be connected to the coil terminals. Connection should be made at the outboard red terminal where the ignition -wvroh lead connects. Suppressors Should be used if radio noise is present.
CABLE ROUTING: Route the four-conductor cable as far as possible from all high tension leads and manifolds, and make sure that the four terminals at the coil (particularly the red and green wire terminals) do not short out against any metal surfaces.
DEFECTIVE COILS: Coils with either shorted turns or primary to secondary
shorts will cause rapid failure of the SCR. If any question exists as to coil
condition, it should be checked on a good tester or replaced. (Do not use
any special high ratio coils with the system. Use standard coils only).