I have dial up. So after 5 munites of waiting I gave up on the video LOL. Can't comment on your form. But I don't see any reason why you can't pull 405, if you mean right now.. well theres one way to find out! Warm up and give it a go!
I'm not sure I understand what you mean by at the beginning of my workout??? If you mean first set! your setting your self up to get hurt real bad!
But if you want to give it a go try this: 135x10 225x5 315x 2 360x1 405x1. Rest 5 minutes between sets. Wear a belt with the last three lifts ( any reason why you picked 405?)
Good luck!! let us know how it go's
Heck I pulled 440 at 132lbs So I know you can do it!!