I'm an 11D on the Franciscan last (333) and for the Dalton. The Dalton fit is fine but close to being too short - the toe has relatively little taper from the widest point and is a bit shorter than some of the other lasts. If I wanted to wear thick socks, I'd go up a half size to 11.5D. Based on that, I'd guess 11.5E would be a good starting point. Disclaimers: your feet are probably different than mine, and comparing single monks to blucher boots is an inexact science.