transmission controlled spark solenoid 70 Chevy Chevelle Camaro Nova 396 402 454

This is a new transmission controlled spark solenoid that fits 1970 Chevy big block models.

Introduced in 1970, the Transmission Controlled Spark (T.C.S.) System controls exhaust emissions by eliminating vacuum advance in the lower forward gears, while at operating temperature.  Often referred to as a T.C.S. Solenoid, this solenoid controls the vacuum to the distributor’s vacuum advance unit. This solenoid determines when, and how much, vacuum to release.  Typically, a vacuum line from the carburetor enters the solenoid and another vacuum line exits the solenoid to the distributor vacuum advance unit (some applications have multiple inlet and outlet lines).  This solenoid also relies on an electrical signal provided by other T.C.S. system switches/senders via an electrical connection on the back or side of the solenoid (the Engine Harness or T.C.S. Harness plugs into this connection).