The ones that look like a "micrometer" are used for Chevy trucks to unload the tension off the bar. There are plenty of examples of homemade tools on the google search for "mopar" specific T-bars.

The Mancini one looks good though shruggy

Gus beer

64 Plymouth Savoy
493 Indy EZ's by Nick at Compu-Flow
5-Speed Richmond faceplate Liberty box
Dana 60