I wanted to give you fellows an update on what's happening with the Milodon pan and Summit Racing.
Summit's tech guy said "put on the stock oil pump".
Milodon said "take two quarts of oil out" it's probably the oil pump bypass. Now, what the hell does taking two quarts of oil out have to do with the oil pump bypass 
Jerks!
They say the oil is foaming and it's the motor's fault. I said there is NO sign of foaming just loss of pressure.
I told them I ordered another pan to end the debate.
I asked them if they would take it back if the pressure doesn't drop when I install the Armondo's pan.
We'll see what response that brings.
Seems they only want your money, they don't care if the parts actually perform as advertised.
There are really two reasons for no pressure at higher RPM's, the pump bypass is open, or you are out of oil.
Bypass open - if the pressure gets too great, as will happen with a lot of flow and always at the upper RPM's, the bypass is supposed to open up and let the pressure go out. If the bypass sticks in the open position, then you will have no pressure until the bypass closes. Normally it opens and closes to keep the pressure consistant.
No oil - If you are using the stock type pickup, those are pretty convoluted on a BBF. If you have a leak in any section including the pump, as soon as you start putting oil on the top of the motor and the pan is no longer completely full of oil, any leaks will cause the pump to suck air as soon as the oil level falls, even if there are several quarts of oil in the pan. You check this by over filling the pan by a few quarts and seeing if you have the same problem at the same RPM.
The other issue could be how it returns. Much like in the olds, where the issue is the oil doesn't return to the pan, if your pan is not allowing the oil to reach the pickup area expediantly, then the pan is full of oil, while the pickup area is uncovered. I don't know if the milodon pan has baffels, but if not, then this isn't your problem.
Another issue could be the depth of the pickup. Too high, and the oil level drops and the pump is uncovered. Too low, and the pan blocks the flow, so at upper RPM's the pump isn't pumping enough GPM, so the pressure drops. You typically want it about 3/8ths from the pan bottom.
I don't know how the windage trays are on the BBF, but I know on the Mopars if the pan isn't cut correctly for the windage tray, then the oil gets blocked on the way to the sump. That may be something else to check.