TV cable set up/adjustment help, 200-4R

[Hogger54]

So I suspected that my "universal" cable was acting up, because it wouldn't go into 4th. Was shifting 1-2 at 17 MPH like some of the instructions I've read say it should.
I bought a TCI cable and swapped them out.
On the install, I took out the cable slack at idle position, then tightened the cable holding lock. Pressed the button and slid the slider piece back to the firewall, then went to full throttle, but nothing ratcheted out. Tried it again, with same results.
Went for a test drive, and shifts were super smooth, almost couldn't feel them. 1-2 was around 5 MPH, and 2-3 was around 15 MPH. But the bonus was that it did shift into 4th.

Little more info: So with the universal cable the truck was just as responsive as it was with my powerglide, but with the TCI cable, it felt sluggish. I currently do not have lockup installed yet.

Do I need to put a little more tension on the cable, or press the button and pull the slider out a little, or is it fine?