Semi Power upgrade?

Hi guys. I haven’t been here for a long time but I hope I can still call on the group for some insight.
I would like to ask what might the outcome be if I purchase a larger diameter valve stem and top hat and keep my existing light (sub 12fpe) spring and hammer? At present my Stealth (Talon) runs just under 10fpe with a two washer preload on the hammer. I only want to push up to 11.5fpe so, would this more generous burst of air necessarily push me over that?

Thanks in anticipation.