Well now THAT is troubling, the fact your old pan DOES have the hinged doors. Which means you may well find the same thing with this new pan. The doors HELP to maintain a decent
oil pressure in the corners, all though it WILL fall some, but it WON'T sustain high
oil pressure in a 'sweeper', it's just not possible. For that you need an Accusump, or a dry sump if your really serious.
If your
oil pressure drops but stays around 20-30 or so, your still OK. It's when it drops to 0-5-10, in that range and your STILL deep in the corner, that it could be trouble.
My oil pressure will drop from 70 or so to about 40 in a sweeper, it will generally stay there as well. But if I'm even a quart low, it will drop much farther, much quicker. These pans are somewhat 'shallow' and you have to walk a fine line between to much and to little oil. To much and your into the windage tray, to little and it has an immediate impact. Measure that oil dip stick with the prescribed 10 qts and make sure it's right when your racing. And don't worry if it drop some, it will, how much is the question!