Went in to pulley up today.
Owen was going to order the 3.65" pulley, but Whipple told us the 3.75" would get us to 10psi. He went with their suggestion and installed it today. We actually didn't get to 10psi...ended up at a peak of 9.3. I'm actually fine with that, because I really just wanted to get over 600. Here are the final numbers.
It ended up the perfect size pulley because we were about to run out of fuel with the stock pump anyway. I think if we go for more I'll need a dual pump (and some forged internals).
This thing is a beast!