4l60 tranny hard shifting sometimes

[61Chevy454]

Kind of similar. Didn't want to make a new thread.

I had my 4L60 rebuilt about a month ago, and i never had kickdown in overdrive. It would never kickdown to 3rd gear and it would shift softly.

Now, after fiddling with the TV cable, it shifts alot harder (Should it? It had a corvette servo, shift kit, etc.), it kicksdown. My only worry is when it shifts. Should it shift into first at 15-20 MPH at not WOT or hard throttle?