Im no expert by far, but pretty sure head spec would be fine for 7500rpm,,
My cvh head on my zvh was still on standard rockers at 7620rpm BUT no guarantee it would last very long! Actually the stud holes for the rockers where modified! Which supposedly makes a differance,

You should speak to harland sharpe in the states for roller rockers, i was speaking to them about a set before i decided to go zetec turbo