Probably yes to both questions. Tips can be changed which will involve the tip assembly and tip holder. Cost to do that may be as much as replacement 7mm units. To do it will also require access to those darn expensive little shims to set the pop pressure. Might contact member NascarMark and see what he says. I know Cummins no longer sells the 9mm injectors for the early type head. Stock injectors for a VE pump engine were 4x.012 unit in the road engines. Those are usually good for a bit over 200 HP and are usually good for what a single turbo can do. The next step up would be the 5x.012 which can put you into the 300 HP area and would need twin turbos.