New valves/ valve springs with new cam?

I currently have an RV cam (not sure of the specs) in a 318 from 1967. I am thinking about upgrading the cam to a summit racing cam (285 duration, .480 lift) or maybe something bigger than that. Would I need new valves or valve springs ( I think the current ones are stock)? Also, would anything have to be changed besides the valves? Thank you