A PT pump is a glorified supply pump. The injectors are where the pressure for injection is generated, so 1st would be different injectors. The injectors are cam operated, so new cam. But wait, there is no place in the head for a third pushtube to pass through to operate the injector... ..... I could go on, but I won't. The short & long, Maybe it is possible, But you would basically be re-designing the entire engine. P.