From the horses mouth.
http://holley.com/data/TechService/Technical/power_valves.pdf
Cant remember what valve i used but started with this as a baseline.
Could be a bad fuel pump,i get dead new stuff all the time,just my luck!How about your pushrod in the block for the pump,was it new?They can wear just enough to where they wont work.
Check your fuel line routing maybe as well,sharp turns,etc.
Used a sender from Mancini,had to "tweak" it slightly,pick up tube hit the
bottom of the tank and wouldnt sit flush to get the lock ring back on.I already
had the sender or i would have used Vans.
I used there tank.Sender was dragging on the bottom of tank when i tried to
install it,just had to adjust a bit.Aftermarket,they may all do that.Price was
right!