LOL, You are doing custom tuning apparently?
I just throw in whatever was in the kit, or whatever matched what I took out. I remember reading about power valves and thought yeah, you could really fine tune an engine that way, but then never took the time to play with them.
Even a poorly sized power valve is better than one stuck, or with a bad diaphragm.
But it sounds like you are 10 levels beyond that trying to get better performance.
Holley makes alternates for just about every part. I have screwed around with jets, squirters, and accelerator pump cams. Never played with power valve.
First it's important to understand what a power valve does. A power valve does not
affect fuel mixture at idle, unless something is wrong. It also does not affect fuel
mixture at WOT, unless something is wrong.
What a power valve does, is control the -timing- of the fuel enrichment. That's all.
The actual -amount- of enrichment is controlled by the power valve channel restriction
orifices.
Some good reading here.
http://vb.foureyedpride.com/showthread.php?161572-4180-baseline-jetting
