oil pressure drop

[2001stang4.6]

Hello everyone ,so the problem I am having is the oil pressure seems fine while crusing around or at idle or even if i just rev it in neutral but under acceleration it drops almost to the very bottom of the gauge. yes i do have the stock gauge new mech one is on order but any ideas before that comes in ? what would most likely be causing this im guessing its more then just a gauge problem.Its a 91 gt 331 with only about 8000 miles on it
Thanks for any ideas .

 

[tannerc91gt]

Just curious, Fram filter?

 

[84Ttop]

is this a new problem or have you had this problem since the motor was built?

 

[MFE92]

That's a classic case of too little clearance between the pickup and the pan...or too little oil