Paul,
I have 2. I dont think orientation makes any difference. I tried pumping
from a gas can on the floor into a gas can on the bench - 5 feet with no
prime. The pump had no problem with this.
Do you have the pumps from Tracy? You mention 45psi. I think Tracy's pump
much higher than that, and you use a regulator to keep it down to 45. Is 45
your pump's max capability?
John Slade