Here are some prototypes of the new Aces that were sent to some local riders. Don't get too excited, they aren't the final design, which, I'm told will likely not be out until Spring 2020.
They were pretty heavy with way thicker hangers and baseplate height. I heard the base plates are going to be thinned out (to keep current height) and come with hollow kingpins stock.
The metal is supposedly way harder. Not 'entirely forged' as people mentioned but apparently manufactured with some process that no other truck manus are currently using. So the grind will feel harder.
These were 44s and they were 8.25". 55s will be 8.5", 66s will be 8.75" and 77s will be 9.125".
I don't know how accurate all this info is but these trucks looked pretty damn sick in person.