Slow crank

On my first picture check out the size of the new battery cable coming from the rear compared to the old original going to the starter. You need a large cable to go the distance. But this may not be your problem starter engagement, tight engine, dirty connections.
I have seen the torque converter not install all the way and destroyed the front pump and bound the transmission. Only you can diagnose the issue. Start looking at the easy first. The first thing I would do is see how easy the motor turns at the damper.