FWIW, when I put my engine back in, it would not crank. Had the same symptoms as yours. Primed, everything was fine, starter was good etc etc.
I ended up just throwing a breaker bar on the crank bolt cause I thought I seized it somehow. I turned it about 1/4 turn and it was fine, hopped back in the car and it turned over and fired right up. I have no idea why it did it, but it takes two seconds to try.