It took me a while but I knew I'd seen this somewhere. (HP Books "Turbo Hydra-matic 350 Handbook")
"1970-74 models equipped with Transmission Controlled Spark (TCS) emission control have a screw-in electrical switch in place of the 2-3 test-port plug." Sounds like it can be removed and replaced with a plug if it's leaking, assuming your car doesn't use it. Pete Geurds Douglassville, PA
