This connection probably doable but will be tight. I say that because in general, EWR is poorly run, and the wait to get through customs/immigration can get longer than it should be. Nowhere else have I had to wait in line for 30 minutes just to hand in the blue customs form at the end - that's supposed to be the shortest step of the whole process.

In addition, I find their border patrol and other airport staff to be exceptionally rude.