I think you can do it man! Proper programming, food and rest. I'm pretty sure you can pull 455. Have you been pulling anything recently? Or after you tested the 1Rm back in august you been taking a break?
A question for you. As tall as you are how do you get around the long lever issue? I have to pull sumo because my arms and legs are stupid long... my arm span says I should be like 6'2" but I'm only 5'10" (Arm span = height theory).