We have very different equipment ('92 2.5L MPFI here), but mine also has a very short prime (like yours). As for the immediate pressure drop ...it sounds like you've already addressed any suggestions that I would've made.
“The test of the machine is the satisfaction it gives you. There isn't any other test. If the machine produces tranquility it's right. If it disturbs you it's wrong until either the machine or your mind is changed.” ― Robert M. Pirsig, Zen And The Art Of Motorcycle Maintenance: An Inquiry Into Values