Truck Bogging down 4,3 V-6 chevy 2000

I need help bad.This problem is really got me puzzled.From the beginning.I had a mis in the engine. Ran the codes and had one described as multible misfires.Changed out the wires,plugs,rotor and cap.This took care of the miss I was having.2 day's later it started dying on me and would not restart until after it sat awhile.Checked the fuel pressure and had very little.Disconnected at the fuel filter(changed the filter 2 day's prior to this)and turned the key on and the fuel just dripped out.Finally sprung for a new pump.Ran fine until the next day when it started to bog down when pressing on the gas pedal.Starts good ,idles good but when you punch it ,it bogs down.Removed the upper intake manifold and cleaned everything up.screen on fuel pressure regulator was not dirty.Did not find anything that looked like it could have caused any problems that I am having.Put it all back togrther and still boggs down.Need some help here.Would a bad fuel pressure regulator cause this problem?Egr moves freely,good PCV valve.Changed out the coil also.Checked fuel pressure today.When the key is first turned on it has 60 psi.When the relay shuts it of it sets at 55psi.The book calls for 60 to 66 psi.Would the pressure difference here cause this or is this normal?It also does this while in park while reving it up.Would dirty injectors cause this?Any replys would be appreciated.

There was a post earlier with a guy and an s10 with a 4.3 i think with a bogging problem , turns out he had a catalytic convertor plugging/plugged up