There's a good article in Hot Rod on spinning the 5.7 and 6.1 at high RPMs
Weak links in the 5.7 and 6.1
Hypereutectic pistons
Stock Hemi main caps break at the 800-900 hp level. Easy fix is a Arrington main cap and ARP studs
Oil pump pickup tube failure. The 6.1 has a added retention tab...