Oh btw, found the pins weren't hollow...
The day they built this for me to demo, I was there waiting & they tossed it out the door quick for me, and then I just decided to take it & it got overlooked. Easy fix!
So how much difference should that make?
It depends on how much weight you are removing from the pin. If the pins are loaded 1/2 full or 1/4 full. It all has different effects on the RPM range.