I did that route last August but stopped at the tarn above Guitar prior to going up. The time from Crabtree to Guitar was about pretty short, but I can't remember the exact time to get there. From Guitar it was 3 hours to Trailcrest with packs and almost 2 hours from there to the summit without packs. We dropped our packs at PC as we exited via the Portal.
Note that if you were going from Crabtree to the summit, you do not pass through Trail Crest. You did pass through the JMT junction twice, and then you ascended to Trail Crest on your way down to Whitney Portal. You don't realize how many hikers make this same navigational error.
