Oil pump/stud interferance
I'm sure they(ARP) have looked into the problem and probably came to the conclusion that ARP can't make a stud and nut that would fit in the space without machining the Cap any better than the factory Chrysler bolt strength wise, so if we want to use the Arp studs it's on us to make it work sort of thing without ARP compromising on the ability of there product and reputation .