I do the screen in the intake valley also..
all my engines have it.. on my first W-2 the
rockers were labeled wrong.. they were B engine
rockers so with the geometry all wrong I had lash
caps on it.. glad I did.. it spit lash caps off on
a regular basis which ended up in the valley.. the
screen kept my spare parts up there and didnt hurt
anything.. back then I thought these things were
made correctly but I sure did learn otherwise..
even when I got the right rockers