Stop in for a cup of coffee

man, im stumped. every im finding speedometer cables show a push in one held in by a bolt. but on all 3 of my push button transmissions, the speedometer hole itself is threaded. Even brewers show it being a push in for 63-65 B body 727 pb transmissions.
There is the gear on the cable, in a holder that is pushed in, and bolted with one bolt. Then the spedo cable is threaded onto that.