Sorry for yet another speedometer cable question but can someone provide some basics..?

My '67 with th350 auto and non-cruise control uses the thread-on type cable at both ends. It appears this isn't really stock since the parts store and catalogs look like they list the push-on type for my application. ? I had to buy one that was listed for a 'lower' end, 4-speed with cruise to get the right ends. Is the 'upper' and 'lower' only for cruise?

Next question, Should the inner cable itself that spins be 'trapped' in the casing length-wise? The cheapo replacement I bought at the parts store is free to move in and out of the casing at the tranny end, which I think is causing it to slip and/or bottom out and stick at the speedometer end.

Next question, who sells a good cable and which one? CI lists an OER brand replacement, another reproduction, and an original GM. NPD lists AC Delco or another cheaper repo..?