There are many ways to do this mod, and for the price it is well worth it.
You can completely remove the hose from the valve, and plug it with something, or put a bleeder type valve (fish tank 2-way) in line to allow the vaccum to escape.
There are a few people even working on a in car system that controls the pump actuation electrically, which is how the pump work normally. Keeping the valve open all the time in first and second gear, as well as below 3400-ish rpm, when under 45-ish mph. Dyno testing of this mod have proven 10 hp gains in first and second gear, as well as 10 ft-lb torque gains in lower rpm ranges throughout.
It might be minimal, but for the $1.50 I spent of the valve, well worth it.
Standing in the shadows with a huge hammer, waiting for all your dreams and hopes to materialize into bunnies!