The E5ss is a VERY light 700. I had a 4035-500 in mine, power house! just run light packs, 4000-4400mAh packs.
Yes the bird I ran in the 2014 IRCHA Speed Cup was a modified E5ss. I had to modify the frames heavily to fit a 14s motor. It ran 137.8 MPH in practice consistently. E5 head, E5 tail, slower tail ratio. 2590RPM with Rail 716 mains. Dozens of practice passes at that RPM. No failures AT ALL.