No fuel pressure with new pump & gauge???

[spaman]

I posted up a few weeks back about issues I was having with loss of power at the top end of the power band. Still having same issues,, Heres what I tried so far.
Many of you guys said the problem sounded like the pump could be the culprit. I replaced the pump with a new mech holley, & also a new liquid filled pressure gauge. I fired the motor, pressure came up to 3# & kind of faded back down to 0#. I then bypassed the tank (ran line from a gas can) still no pressure. I went ahead & test drove the car anyway since it idled fine. When car gets to high end of 3-4th gear it still noses over.. Came back pulled pump & fingered the pump rod while turning over motor. The rod is only moving about a 1/4inch. It is a hardend rod looks fine. I had someone tell me the rod should be moving 1/2in or more to activate the pump properly. He thinks I've wiped the lobe on the cam... I'm at a loss here. Whats your thoughts on what could be going on here? Thanks