I visited Mr. Grose at his basement shop in the late '70s in Mass. We talked about his invention and why he came up with the idea. I had been experiencing fuel starvation in hard cornering with a Porsche and thought baffling was the answer. He explained that sometimes the centrifugal force was keeping the needle stuck closed in the seat and as the bowl emptied the main jets sucked air. The Grose jet has two balls in the cage, one to contact the float and push the smaller ball up to shut off fuel when the float level was correct. The Grose jet is not subject to the centrifugal force; the small ball uncovers the fuel opening in the seat. I found that setting the float level was extremely important (sometimes very thin fiber washers rather than what was supplied in the kits).
He manufactured many different versions of the jet depending on the carb in which it was to be installed. The two differences were the size of the opening for the small ball (flow rate into the bowl was determined by size but fuel pressure was usually low 2-4 lbs), and thickness of the seat/cage that screwed into the carb top.
I've used Grose jets in many different carb applications both in racing and on the street and never had a problem. But initial set up float height is critical.
Regards,
Chuck