You said the the feed to the cam is a little small, that would effect top end oiling I think. Seriously the only issues I have heard of were with stock 5.7 cranks and the stock 6-7 qt pans getting emptied by the end of a pass when people start eclipsing the 7k mark. Barton IIRC used a 12 qt pan and was going through the traps at 8900. How much RPM are trying to run? The exhaust valves and rockers are oiled from the being submerged in oil while running so anything to increase drainback would be probably the best oil mod IMO. LIGHT oil seems to be what the engineers leaned on, all 6.1, SRT 6.4's and the Hellcat 6.2's were designed with 0W40 in mind. This returns to the pan pretty quickly.