I have a 350 in my Camaro, and whenever I push the throttle at any degree of hardness, the oil pressure drop all the way to 0. Then it steadily builds back up to around 45 to 50PSI. Then when I stop it does it over again, or when I mash the gas to the floor. I am using 20W-50 oil, if that helps any.

 

Why are you running molasses in your engine first and foremost?? Makes me think your covering up a bigger problem, very 70's mentality with the thick oil.

Anyways, first place I would personally check in pick up to pan clearnace, sounds like it might be too low in the pan. Drain the oil and try and sight up through it with a flashlight, pick up shouldbe about 1/4" off the pan floor. If nothing else, jack up the motor and drop the pan to verify/fix.