Would self aligning rockers still be needed now that I'm having screw-in studs and valve guides installed?

 

nope

 

Like he said, nope. The guideplates do exactly what their name implies - they guide the pushrod. They keep the pushrod from having too much movement which, in turn, would give the rocker arm too much movement to the point that it could move off the valve stem. Not exactly an ideal situation if that happens. So guideplates basically keep the rocker arm in place on the valve stem. That is the same task that self aligning rockers perform except they do it with small ridges on the edges of the rocker or washer-type plates on the ends of the rollers on roller tipped ones. One system will be fine on its own and in some situations running both SA rockers and guideplates will create bind and cause valvetrain component failure(s).

Hope that helps,
Matt