I know "zip" about impressive calf lifts but I worked with a good friend and watched him load an incline calf machine to a max of 765 lbs and do 3x8.
At Gold's a friend of his claims that he did that much wt plus two of the heaviest guys in the gym sitting on the wt stack for a total lift of approximately 1,200 lbs.
That 765 that I personally witnessed impressed me but I guess that 1,200+- wouldn't impress most of you big time lifters.
Anyone see him getting photographed on the Squat Rack last Friday? Damn impressive bodybuilder.