[Wagonized]

thats all pretty common stuff when ur lifting heavy. The main thing I try to focus on when Im going big is keeping my shoulder blades back. I need to stay tight and try to shorten the stroke of my arms as much as possible. Im 6'4 and if i dont keep my shoulder blades back I can usually put the bar right over the supports with my arms straight. Which puts me at a huge disadvantage.

Your arch is also important. But not necessarily as important as you think. Some people are stronger with a huge arch while others like myself lift bigger with a mild arch.

Also your grip width is a huge factor. Atleast it is for me. Too wide and Ill shorten my stroke even more which is good, but I lose the explosive drive at the very bottom of the lift.

Search Ryan Kennely on youtube aka benchmonster. Theres a few good clips of him benching big. He doesnt have your typical powerlifter body either, hes rather tall and not as fat as most of the super heavyweights. Trains in MMA aswell.