I would add that if your sender is installed on the original factory provided oil port that even thought you have likely not installed restricter sleeves in the lifter bores and you have all of those corresponding oil losses through the lifter gallery, you STILL have more then adequate oil pressure in the system.
If you are running a hydraulic lifter camshaft then I wouldn't change anything. If it is a solid lifter cam, you need to use the Johnson oil restricter type that were originally designed by Ford for the Boss 351 solid lifter cam application.
Sleeving the lifter bores is a good idea but it is for the purpose of keeping oil in the 5 quart pan and to avoid running out of oil at high rpm use.
It isn't just the Clevelands that do this, the FE Fords particularly when the 428cj was introduced in the 68 model year with oil starvation warranty claims. Strange that it didn't show on the 427's to that extent but the documentation is there to show it was a lack of oil capacity and the engine was pumping the pan dry over only 5,000 rpm.
Shelby installed a larger capacity oil pan, the T-COBRA aluminum pan, on the 65 and 66 GT350's which were 289's. All Fords can pump the pan dry. I had a 76 Granada with a 302 that did it. There it actually siphoned the oil out of the valve covers into the intake through the pcv system.