can i use the stock vortec rockers with the lt4 hot cam springs and a zz4 cam? thanks

Depending upon the rocker stud slot length in the rocker, they may work. However, the rockers will tend to flex at higher lifts, and you will lose valve action to the flexing. You will have to assemble one pair of valves, lifters, rockers, and push rods and cycle the engine by hand to check clearances.

If they work without binding at the rocker studs, they might be good rockers to break in the engine. The LT4 hot springs are not that much higher pressure than the stock 85# springs, but they are better.