1973 360 upgrades

it should start to move right away. Also, under wide open throttle the kickdown should be almost all the way pinned back. So you will push the throttle to the WOT position, then use the other hand to see how much more you can push the kickdown back. I like only about a 1/16th of an inch more action from the kickdown under WOT
I watched your video on this. What little I have driven the truck the tranny is not shifting right I’m hoping it’s the kickdown