I too think the nozzles are too small, i run 32's with a 0-1/2 on a 377" bowl with .085/.095 depending on the weather, my friend runs #35 nozzles with a bowl and 421" with .070/.075. I'm thinking you need atleast 35's/37's with a 468" motor.
I run 22% leakdown with the blade set at .005, we don't run a hi-speed bypass.
JMO
Zip.