TCS Relay, 1970-75 GM A-Body

This reproduction relay is identical to original equipment and is a must-have for any 4-speed vehicle. The relay works with the Transmission Controlled Spark (TCS) switch to advance the engine timing when the transmission is in top-gear, which provides better fuel economy. The original style relay is stamped with the original GM part number on its zinc-plated metal top and also features a plastic body equipped with the correct four-prong configuration. Sold per each.